or you could just wait, ring him up by phone and talk resobly to him?
instead of getting all stuck up saying "he stole ma gad damn mone ill kik his arse, im well bult i am"
find out whats wrong, if it looks like he pulled a runner, with your money, contact Ebay like Dataforce said... and also tell the police were his adress is, saying he is a fraud(and how do you know it his own adress)