This morning I tried to get a complimentary upgrade on my B fare flight from SFO-ORD. My fare was BEE. When I asked the check-in agent, she was not familiar with the program so she called in to inquire. They told her that this only applied to "full fare B and Y fares."

So what qualifies as a full fare B or Y fare. Does anyone have any experience suggesting that they made a mistake and that my upgrades should have been complimentary. I am curious about what gives here since I did purchase a B fare which is changeable and refundable (not a 3 day advance purchase).