I for one am sorry for the frustration you went through, but I am glad you posted your story. For me at least, it is an opportunity to think through what I would do. About the worst possible scenario is to be unable to prove anything. Conversely, the worst possible scenario for CO is for a full fare F customer to put themselves in a position where they cannot be ignored. Consequently, I think I would have made a bit more of a stink and risked getting booted if that's what it took.