Hey,
I think what you should do is go down to small claims court (if under $2000) and talk to someone down there and tell them your problem. most of the time as long as you have witnesses and all his info you should be able to sue him and either get the work done or get the money back. It's a hard way to learn a lesson but when doing things that involve a large amount of money you should always give a check or get a receipt, and have him write and sign a contract stating the work, price, and date(s) the two of you agreed to get the work done on.

Good luck and hope you can get your money back from this Jack A$$.