There may or may not be other causes of action, but the "broke the contract" one definately won't fly. A person suing over changes to AAdvantage a few years ago tried this. AA's response to the court basically was, "You want to talk about the contract? Well, judge, here's a copy of the contract" and pointed out the specifics that were in the Contract of Carriage and AAdvantage terms and conditions. You can't say they "broke the contract" and then just make up what you think a fair contract, in your opinion, would say.