CanadianFlyer,
I was told that once before -- don't stand for it. At the time, I had tickets purchased in K class. The agent tells me that I am not eligible because there are no seats left in K class, and the fare, if I would purchase it today, would be significantly higher. I responded that there are seats in K class. They're the ones I'm holding. I was insistant, and asked that they check again with customer service. They issued the write down.
Simply put, if you are holding a ticket with a particular fare basis (e.g., L, K, H, etc.) and they lower the price for that fare basis, you should be entitled to the difference regardless of whether seats are available at that fare basis.
It is unfortunate that you have to go to the CTO or Airport. Perhaps because I purchased on their website, DL offered to mail mine to me.
[This message has been edited by A Delta CUSTOMER! (edited 03-01-2000).]