Just to add my rather depressing story..
I've also been banned: I use(d) Play on Linux to get D3 working, but Blizzard have accused me of cheating... I'm not sure at what as I've never played a coooperative version of the game or used the Auction House.
They've provided no evidence or description of what 'unfair advantage' I had, nor have they responded to my request for a refund..
I've raised a 'consumer complaint' with the citizens advice bureau
I'm also considering going to the small claims court
They're accusation has really p****d me off