We can't really do much to help if we don't know who it is.
Here's the basic things you can do.
Post his name for all to see.
Take him to small claims.
Call the police and claim fraud.
If you sent the money via PayPal contest the charge on your Visa/MC
If you sent the money via EMT complain to your bank.
Not do anything and be out how ever much cash you sent.