Can I file a police report or complaint to get the mechanic to finally have my car repaired?

Around the last week of September 2013 I bought a Honda Civic and it did not have a transmission. So I went to a mechanic and asked him if he could get me one and he said yes. And when I bought it he did not want to give me a receipt and I kept telling him I wanted my receipt but he said the transmission would last me a long time so I did not need it. He gave me 30 days of guaranty and 2 or 3 days before my guaranty expires the transmission messed up. I called him and told him what happen and at first he did not want to give me another transmission but then he finally said alright. I left the car with him November 2013 and to this day April 10 2014 I been calling and asking him when my car would be fixed. He just says "wait just give me more time" and last time I called on March 2014 he said he just barely bought the transmission and to this day he still has not fixed my car. I also paid him more money for the new transmission even though I had guaranty on it. I would just like to know if I could file a police report or something so I can get my car fixed already. It is about to be half a year that he has it and I had bought brand new tires for it, I'm afraid there bad now for sitting there too long. I'm a student and in May I'll be going to another state and study. I need my car really bad. What would be the best thing that I can do now? Thank you so much.