Why was i banned?

Why was i banned? A guy i sold a previous account claims i recovered an account off him which isn't true he still has the account, but i know theres no way i can prove it as its his word against mine. But i don't know why he would try and shut me down after we had a good trade... he has no evidence that i recovered my account off him, so why has he been listened too... So i was guilty from the start and not even given a chance to prove my innocence which i think is very unfair and wrong

 

So recover the account for him and give it back to him.