The auto body shop where I took my car was recently broken into. My car glass was broken along with 12 other cars. The repair shop says they are not responsible for the damage. The lot was not secured and no signs posted. I did not sign any release. As the car is old, I carry only liability insurance. Shouldn't the shop have some insurance to cover this type of damage on their premises?
Regardless of insurance, if you never signed a "Hold Harmless" clause in the Work Order, and everything else above is true, then they owe you for the damage.
So, if all is true, and they still won't pay you for a replacement and labor, then you'll have to get your own estimates (at least 2), and sue the shop in Small Claims court.