Our first flight was sold as an A fare, so first class. We were initially on an earlier flight, then put on a later flight in December. I think it was 2 class at that point and now it is 3 class. First is oversold and we have no seat assignments. Yet AA is offering 1 seat for sale on the flight. What is AA's obligation to us if on the day of travel they are not able to give us seats in F?