paypal Unauthorized Payment problem with the buyer

Ok, some guy bought my ebook and downloaded it and I received this on paypal. I really don't know what to do. Please help!

 

I seems that you are a Victim. There must be three possibilities of fraud and i don't think there is any fault of you.
1. The buyer paid through his or her account and the file a complaint against it. He is very cunning.
2. Owner of account some how reveal his password. He is stupid and Victim too.
3. Someone hack paypal and make payment through account.

Where is seller's fault?

 

You'd better give paypal a call,then upload all documents to them,good luck

 

i think that the deal was unsatisfactory so he had placed dispute.................................