I don't think you need to sue. Just call your insurance company and tell them what's going on. (I am not clear if you've been talking to YOUR insurance company or the other guy's insurance company... but you should definitely be working through your own insurance company.) We were rear-ended and even though we had the other guy's insurance information, we just called our own agent and told her about it, she immediately started a claim and took care of us. At this point, the body shop committed insurance fraud and left you with an unsafe vehicle. Immediately, the insurance company should get your car into the shop and repair it. Then they can go back after the crook who worked on it in the first place. Bottom line, this is why you pay an insurance company - let them with their army of lawyers deal with this for you! Good luck!