If you file a police report as stolen, and report it to the dmv as stolen, I suppose you can move forward. But you still don’t get your car back restored. Take a friend or 2 to his shop and record everything he says. Then go record what your car had on it when you dropped off. Go to his car and record what was yours that’s now on his. If he says to not go in the shop, go anyway. If he threatens to call the police, tell him to go ahead and do it. Record it start to finish, without stopping, (You can always fast forward past the dead spots) and I’m sure his reactions and comments will support your claim. Video evidence doesn’t lie, and your lawyer or any judge will most likely side with you. It sucks there are people like this in business.