mechanic stole my car, help!?

[Stamenoff]

I bought a use car a few months ago. the car has some electrical problem, so I search for a mechanic on craigslist, stupid! I find a guy, who said that he is porfessiona it electrical issues, and he promise to fix my car fast and cheap, I tow the car to a address that he give me to get repairs. I paid half up front. I called to see if the work was finished. He tells me that he just needs to take care one more thing and its done. its been 4 months with no responde form him, he call me from time to time to keep me waiting, now his phone doesnt work, so I went to the address, my car is not there and nobody get the door for me. i send him e-mail, and he respond that he doesnt have phone right now and my car is at shop couse need some computer check up. Well, its been another month, he just keep sending e-mail to make me wait, but this is unbelivable, in 2011 to have no way to call me...i try to find him at his work at local dealer but he doesn't work there anymore and the car isn't there either! what is the legal way to get my car and my money back? Can I sue this guy and get my money back? What about if my car is already take on a part, and sold!? How do I go about this? Please help!