Hopefully Karen or Paul can give you some insight.

Does the friend who emailed you have any idea who it is?

All I can think of is reporting this to your IP, but I don't really know what they could do but dispense advice.

Maybe in a couple of months, reapply with a new screen name. If the password abuse has STILL been going on, they'll know it's not you, and may re-admit you.

It IS really rude that they don't give you an answer or explanation!

Good luck with this.