Q: Last year, I booked a ticket from San Francisco to Munich. A few weeks later, Lufthansa informed me that the flight had changed and that there would be a stopover in Frankfurt. Given that, it was more convenient for me just to terminate my flight in Frankfurt than to continue on to Munich.

I called Lufthansa and asked to change the ticket to Frankfurt, confirming that the change did not increase the price. I did that on the phone, noting the time and the representative I spoke to.

When I went to the ticket counter on my flight day, a Lufthansa employee told me that my ticket to Frankfurt hadn’t been paid. How was I supposed to know that? I was under the assumption that the original charge was still applied since the representative told me on the phone it would be exactly the same price. This was a complete surprise to me.

Lufthansa made me pay a walk-up fare of $2,360.

I have been fighting with Lufthansa since last July. The airline emailed back twice but obviously had not even read my email. In my last email, I just asked two very specific questions. I haven’t received an answer in five weeks. All I want is a refund of $1,360, which is the fare difference. Can you help?

— Gabriele Stahl, Campbell, California

A: Lufthansa should have done what it promised you by phone: changed your flight from Munich to Frankfurt without charging you. The problem is, you don’t have any evidence that the phone conversation happened. The airline does; it records all calls for “quality assurance” purposes.

Until we’re on a level playing field — until both sides can legally record the conversation, and do — we’ll have problems like this.

The written correspondence between you and Lufthansa is frustrating for me to read. It looks like you spent many hours trying to secure a confirmation for your new flight, to no avail. Finally, you just went to the airport on the day of your departure, hoping for the best.

If you ever find yourself in this situation again, make sure you have a confirmation number for the new flight. It looks as if Lufthansa didn’t do what it said. Instead, it canceled your old flight and issued a full refund. Then it made a new reservation and waited for you to pay for it. That’s not what you wanted.

I list the names, numbers and email addresses of the Lufthansa executives on my consumer advocacy site at www.elliott.org/company-contacts/lufthansa-airlines/. Unfortunately, Lufthansa almost never responds to my nonprofit organization’s inquiries, so I recommended that you send a brief letter of complaint to the U.S. Department of Transportation.

Lufthansa refunded the fare difference. I asked Lufthansa to comment for this story, but it didn’t respond, as usual.

Christopher Elliott is the chief advocacy officer of Elliott Advocacy, a nonprofit organization that helps consumers resolve their problems. Elliott’s latest book is “How To Be The World’s Smartest Traveler” (National Geographic). Contact him at elliott.org/help or chris@elliott.org.