The first thing you should do is contact your insurance company. An agent or representative should give you an exact reason why they denied your coverage. Also, check your mail. Insurance companies must send a letter explaining why your coverage ended.
You should also reach out to the body shop if you haven’t already. They are responsible for the quality of their work. If your vehicle still isn’t fixed, they should be willing to look at it again to address any issues with their work.
Should you be unable to resolve the issue with your insurance company, you can submit a complaint to your state’s Department of Insurance. You also could visit a lawyer that specializes in car insurance claims. Many offer free consultations, giving you a better idea of what to do next.