Re: Used and Abused.
Hmm...I re-read your post a few times. Sorry, I don't think you have any evidence against your classmate.
It sounds like a totally nasty and frustrating situation. The only thing you can really do is try to talk with this guy, or his other bandmates, and try to wrap up the situation in your own mind the best you can. This seems like the type of situation you'll be thinking back to with a negative view for years to come.
The good news, though, is you learned to get things in writing. At this early in the game, too! :D