Hmm.. ive had seen so many "i got hacked how do i get back?" or "how do i block em, i know the guy" questions..

No offense to you but id like to be thorough.. coz most likely, the person didnt do it, he just wants to scare u or something, or taking advantage of the situation.

None the less,.. can u tell me.

What made u think you were hacked?
What happened? (symptoms)
Who is this guy and what does he want with you?
Has he made any solid proof that he did it?
How did he do it?

answer all those and i can prommise u, i can give u a fair solution to ur problem.