What would you expect, man.. always ask for a upfront fee, like 30%.. and then the rest of the payment once you've finished the website and handed him the logins to the backend. Lol.. he took you for a ride.. you'll learn from now on to at least get an upfront payment.
As Techxan says.. just build another website(s) and out rank him. He's not going to pay you but he defintiely just gave you a lesson you are not going to forget.. And throwing a brick in his window or threatening him on twitter will just cause you more trouble.