I hired a contractor to build a 2 car garage, he never started the job and won't return my money to me...what can i do?

it's been almost 5 months now and I paid him almost 18k already, he claimed he needed the money to purchase materials, hire architect etc...but to this date he hasn't filed a single paper for permit or purchase any materials or anything else. i have a contract and receipt of the money that was given to him. now when i call him, he hangs up the phone on me or treatens me and tells me not to bother him. after doing my own research and talking to his family members, it turns out this is his normal routine and he has done it to many others.