Q: I recently booked a one-way ticket on American Airlines from Philadelphia to Palm Beach, Florida, through Travelocity.com. The flight was oversold, so the airline put me on standby for another overbooked flight on the same day and arriving in Orlando, Florida — more than two hours away from my desired destination.

I did not get a seat on that flight either, and could not travel. According to the U.S. Department of Transportation’s Passenger Bill of Rights, I am legally entitled to 400 percent of my original ticket price because the flight that American tried and failed to get me a seat on was over two hours past my original arrival time.

My original ticket price was $177. In addition, I paid $19 for flight protection, so the airline should be refunding my ticket regardless. I was packed and ready to go, I couldn’t make my trip, and I lost hundreds of dollars in prepaid expenses because of American’s mistake, and now it is refusing to reimburse me for anything.

I sent multiple emails and kept being denied reimbursement. American is breaking the law by denying me a refund. I want the legally required amount due to me: 400 percent of $177. I also would like the $19 in flight protection refunded, since that apparently means nothing to the airline. — Samantha Gomez, Coatesville, Pennsylvania

A: Overbooking, or selling more tickets than seats, should be illegal. But in the upside-down world of the airline industry, it’s a common and accepted practice. The only thing stopping an airline from overselling more seats are Department of Transportation regulations that require an airline to fork over a refund, and then some, if it can’t get you to your destination.

Your rights are outlined in the DOT’s brochure — FlyRights — which you can find online: www.transportation.gov/airconsumer/fly-rights

American Airlines should have offered you a written statement describing your rights and explaining how it decides who gets on an oversold flight and who doesn’t. You were entitled to denied-boarding compensation in the form of a check or cash. Based on your correspondence, it appears that you received none of those things, which is a clear violation of DOT regulations.

You could have sent one last appeal to American Airlines (I list the executive contacts on my site: elliott.org/company-contacts/american-airlines/). You also could have filed a complaint with the DOT online: www.transportation.gov/airconsumer/file-consumer-complaint

I contacted American and your online travel agency, Travelocity, and got to the bottom of the mystery. Travelocity’s records suggest that you missed your flight, not that you were involuntarily denied boarding. But your online agency contacted the airline to see what its records say, and after some back-and-forth, American agreed with your conclusion that you’d been denied boarding. American paid you three times the value of your ticket, in accordance with DOT regulations.

Christopher Elliott is the ombudsman for National Geographic Traveler magazine and the author of “How to Be the World’s Smartest Traveler.” You can read more travel tips on his blog, elliott.org, or email him at chris@elliott.org.