Took my money and refused to finish work!

We signed a contract that he would build me an ecommerce website within 33 days and I would pay him in 3 installments, the last payment due when the site was finished. I paid him the full amount in advance. After that I could hardly get anything from him. I got numerous dates when he would be finished, all came and went with no site. He even told me once all his computers and backups crashed and he had to start completely over. 5 months later, he finally gave me an unfinished website, the cart wouldn't work, the pages were not finished, and it was full of errors. Then when I got so tired of waiting for him and not getting responses from e-mails, I contacted another designer to look at it and tell me what it would take to finish it. As soon as he saw that another designer had been looking at it he dropped me and refused to work on my website any further. Even demanded more money. My entire business is put on hold because of it, and on top of the $2400.00 I paid him 5 months ago, I have to pay another web designer to finish it so it's even usable. Not to mention both the designers I have had look at it said the backend he used to make the website is crap and I'll eventually have to pay for a complete overhaul to the site.