Q: I recently flew from Chicago’s O’Hare International Airport to Ronald Reagan Washington National Airport on United Airlines. The gate from which I was boarding my flight in Chicago was a shared gate with another United flight leaving at approximately the same time, and there was much confusion boarding both flights with shared gate attendants and ticket scanners.

When I tried to confirm my return flight home, I found that my confirmation number was no longer valid because United had canceled my return flight, claiming that I did not use my seat from Chicago to Washington.

A United representative told me that my return-flight seat had been sold and that if I wanted to return to Chicago, I needed to book another flight, pay a $200 change fee and then attempt to receive a refund from United Airlines for the change fee. Ultimately, United denied me this refund.

All I want is my $200 fee returned and my miles for the Chicago to Washington credited to my United Airlines account since I took my original flight. Can you help?

— Michael Del Medico, Park Ridge, Illinois

A: United shouldn’t have canceled your return trip. You were on the outbound flight to Washington. You had a roundtrip ticket. You should have been able to fly home. End of story.

Unfortunately, that’s not what happened. You recall some confusion at the gate, and for whatever reason, United did not have a record of you on your outbound flight.

Canceling the return is a normal — and understandable — industry-wide policy. If you miss your outbound flight, an airline assumes your seat will fly empty on the return as well. Canceling the ticket allows the airline to resell the seat.

When you told United that you were on the flight from Chicago to Washington and offered to show it proof, that should have been an easy fix. But the system isn’t set up like that. After an automatic cancellation, your seat is released back into the airline’s inventory, and you need to go through the booking process again. A $200 change fee is a given. Never mind the fact that these change fees are nothing more than a money grab by the airline. (Does it actually cost the airline $200 to change a ticket? No.)

It’s not clear why United insisted on charging you again and then asking you to go through the refund process. That’s probably a function of its accounting system, as opposed to the way it would handle customer service. I imagine there are United employees who would have wanted to fix this, but their hands were tied.

I contacted the airline on your behalf, and it refunded the $200 and credited your miles.

© 2017 Christopher Elliott. Distributed by King Features Syndicate, Inc.