He accused you of scam because you banned his account for no reason other than being butthurt because he said he was leaving the filehost, something that is childish from both parts, but you're taking away a service he paid, that pretty much is a scam, you offered 3 months of service for X ammount of money, and if he didn't break the TOS, nor failed to paid the X ammount, you have no right to remove his account, and he stated that he was banned for no reason, and looking at your "proof" he seems to be right.
PS: I love when someone post a time line that helps you to prove that he is wrong.