Dispute on E13m3n7

I sold him my 7 digit steam account with cod4/cs1.6 and css on it, for $30.00.
About 20 minutes later i receive a dispute on paypal from him saying "Well I ordered something from this guy, and after I sent the money he said pz kid. And blocked me on msn. I doubt I'm going to recive my product, so until the product is recived i want my 30$ back."
I have a SS of the dispute on paypal, But I dont have an SS or log of the MSN transaction history as my msn currently wont let me view any history.
He buys with paypal and then tries to take his money back by disputing it on paypal.