My Car was stolen from Pep Boys this weekend need advice on what to do HELP.

I scheduled an appointment online at pep boys for Saturday 9:00 am. I went in at 9, filled up a form with my name and phone number and the service that needs to be done on the car. they requested for the car keys to work on it and they said they would call me back when they are done. So I went home till they finish. Then, I got a call from them at about 10:21 am saying my car has been stolen. They called the cops and filed a case. I already called my insurance company, but since I have limited liability for the car, they are not covering it. It's a 2007 Toyota Camry. It happened in Baltimore Maryland. I feel like the are fully responsible for it, but one of the manager is saying they are not responsible for it. I am not sure how to go about it.