Dear Tripped Up,

Last summer, I booked a five-day sailing trip with Tall Ship Experience, a company based in Spain. For 1,350 euros, or $1,450, I would be a volunteer on the crew of the Atlantis, sailing between two ports in Italy. But eight days before, I had a bad fall that resulted in multiple injuries, including eight stitches to my face that doctors said I could not expose to sun or water. The Tall Ship Experience website clearly states that I could cancel for a full refund up to seven days before the trip. But the company revealed it was just an intermediary and the Dutch organization actually running the trip, Tallship Company, had different rules, under which I was refunded 10 percent. I offered to take credit for a future trip, to no avail. Finally, I disputed the charges with my credit card issuer, American Express. But Tall Ship Experience provided a completely different set of terms to Amex, saying I canceled one day in advance. The charges were reinstated. Can you help? Martha, Los Angeles

Dear Martha,

This story reads like a greatest-hits playlist of travel industry traps: a middleman shirking responsibility, terms and conditions run amok, a credit card chargeback gone wrong, and the maddening barriers to pursuing justice against a foreign company. However, the documentation you sent was so complete and the company’s website so confusing that I was sure Tall Ship Experience would quickly refund you.

Tallship Company did not respond to requests for comments, but did nothing wrong. It simply followed its own terms and conditions that Tall Ship Experience, as a middleman, should have made clear to you. When you canceled, Tallship Company sent back a 10 percent refund to Tall Ship Experience to then send to you.

That’s why I was surprised that the stubborn (though exceedingly polite) Tall Ship Experience spokeswoman who responded to me on behalf of the Seville-based organization argued repeatedly that although she regretted your disappointment, Tall Ship Experience was not at fault. At one point she suggested you should have purchased travel insurance, even as the company scrambled to adjust and update its website as we emailed.

Before the changes, the site contained two distinct and contradictory sets of terms and conditions: one for customers who purchased via the website’s English and French versions, and another on the Spanish version. (Confusingly, both documents were in Spanish.)

The English/French version — the one you had seen — promised customers a full refund for trips canceled more than seven days in advance. The Spanish one is vastly more complex, offering distinct cancellation terms for each ship. The Atlantis offered customers in your situation only 10 percent back.

Enter the stubborn spokeswoman: “The terms and conditions in Spanish correctly reflected the cancellation policy of the ship in the moment the client made the reservation,” she wrote via email. “We are conscious that at the time, the English version of the terms was not updated, which may have generated confusion. However, the official terms of the reservation were applied correctly.”

In other words, customers should somehow know to ignore one contract and seek out another on a different part of the site, both in a language they may not read.

But I am no expert in Spanish consumer law, so I got in touch with two people who are: Marta Valls Sierra, head of the consumer rights practice at Marimón Abogados, a law firm based in Barcelona; and Fernando Peña López, a professor at the Universidade da Coruña in A Coruña.

They examined the documentation and each concluded independently that Tall Ship Experience had violated basic Spanish consumer statutes. When I passed along their convincing points to the spokeswoman and alerted her that you were considering taking the company to Spanish small-claims court, she finally said it would refund you the remaining €1,215.

I felt a bit sheepish about exerting so much pressure on this small company — actually, an arm of the nonprofit Nao Victoria Foundation, which operates several replicas of historic ships — but the company should have taken much more care when it set up its website, Ms. Valls Sierra told me.

“If in your terms and conditions you say that up until seven days before departure you have the right to cancel,” she said in an interview, “and a consumer comes and says, ‘I want to cancel,’ you have to cancel their trip and return their money. They can’t use ‘Sorry, we forgot to put it on one web page, but we put it on another web page’ as an excuse.”

It is a principle of consumer law, she added, that confusing or contradictory contracts are interpreted in favor of the consumer.

The other troubling issue with the website is that you had no way of knowing that your trip was not operated by Tall Ship Experience. There was no such mention I could find on the website, which relies on marketing copy like this: “On board you will learn everything you need to know that will allow you to become one of our crew.”

Dr. Peña López, the law professor, wrote me in an email that “Tall Ship Experience is obligated to inform the consumer about the service it provides in an accessible and understandable manner, clearly indicating whether it is an intermediary.” He added that Tall Ship Experience “clearly” presented itself as the ship’s operator in this case.

As I mentioned, Tall Ship Experience did begin updating its site almost as soon as I got in touch, calling itself a “marketplace” for experiences and posting the correct terms and conditions (in the correct languages) on its English and French pages.

But Tall Ship Experience agreed to a refund only after I sent the company a compilation of the two experts’ legal analyses. “We are dedicated to creating experiences aboard unique boats, and not to legal matters,” came the spokeswoman’s response. “Regardless of which party is correct in this case, we would like to refund the full amount. We look forward to putting this to rest and to focus on continuing to improve customer experiences.”

You also said that American Express had let you down, by taking the company’s word over yours when you contested the charge. It is true that the document Tall Ship Experience sent to Amex (which forwarded it to you, who forwarded it to me), is wildly inaccurate, including only the terms favorable to the company and saying you canceled only one day in advance.

A spokeswoman for American Express emailed me a statement saying that the company “takes into account both the card member and the merchant perspectives.” But travelers should not mistake credit card issuers for crack investigators who will leave no stone unturned in pursuit of travel justice. A chargeback request works best when the problem is straightforward — you were charged more than you agreed to pay, or you never agreed to pay at all. Asking your card issuer to do a deep dive into terms and conditions is a much longer shot.

And as we’ve seen before (and might be seeing in this case) such chargeback requests often anger the companies involved to the point that they refuse to deal with you further.

If all else had failed, as I told you before the company gave in, you could have requested a “juicio verbal,” Spain’s version of a small-claims-court proceeding, via videoconference. It would not have been easy, said Dr. Peña López. Cases under €2,000 do not require a lawyer, but they do require you to have a Foreigner Identification Number, to fill out forms in legal Spanish (A.I. might help) and to find an interpreter to be by your side.

When I finally told you — in our 39th email! — you’d get a refund, you told me you had been “almost looking forward to a Spanish small-claims experience.” I admire your spirit, although I suspect it would have been quickly broken by bureaucratic and linguistic barriers.

If you need advice about a best-laid travel plan that went awry, send an email to TrippedUp@nytimes.com.

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