I do not disagree mahasamatman about the rules, per se. As I mentioned, I will accept them closing my account because it is possible I was in violation of their internal T&Cs. Hey, even if they want to ban me from their airline, so be it. In my eyes, that is their loss.

What I am having trouble seeing is how their internal rules could translate into actual legal recourse against me. It is one thing for a business to institute a policy, but that does not necessarily mean they have legal rights based on the policy. In many cases, a company's only recourse is to refuse to do business with a client in the future.

I concede that had they learned prior to travel that I acquired the TravelBank funds through a method they deemed violated their internal policies, they could void the contract of carriage and do anything up to and including close my MP account and refuse to do business with me again in the future, but would that not be the extent of it? Remember that TravelBank funds are not legal currency, and have no such equivalency to legal currency anymore than a gift card does. They chose to accept my TravelBank funds as valid for purchase of travel, and allowed me to actually travel. How can they come back seven months later and say I now owe them cash because my original ticketing method is no longer valid? I did not purchase the TravelBank funds from UA, I acquired them from an outside source. In my eyes, their only legal recourse/actionable loss would be against the original TravelBank purchaser. If I am misunderstanding, please educate me.