Start Mart ripoff and theifs Englewood Colorado

Being only 17 and short on money, I took my car to Start Mart to have the broken starter replaced. I call them and they send one of their tow trucks out to retrieve my car. I was told to come get it the next day. I come into the building and pay and receive the key and the mechanic says it's parked out back. Well, out back is a strange alley. Upon getting into my car, I realize its not locked and my nearly $300 radio has been stolen. The mechanic says it's not their problem and how do they know it wasn't in there when they got it. Then he begins to blaim it on the tow driver. My assumption is that the mechanic himself stole the radio. Please let me know if you can help me.

Uller
Conifer, Colorado
U.S.A.