I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
The repair shop is unfortunately not legally responsible for the criminal acts of third parties, unless they are somehow responsible. In court, a lot of people think the responsible party should be the one who has more ability to pay, but that's unfortunately not how it works. To recover against someone, you have to show that they did something wrong. Being broken into isn't their fault. Most repair shops have signs or waivers in their paperwork that disclaims liability for certain things that happen if the vehicle is in their car, such as if they are negligent and the vehicle gets stolen. Read through every piece of paper you have carefully, or go in and look to see if they have signs posted around the shop. But even if they don't have disclaimers, the criminal acts of a third party usually cut off liability for negligence.
What that means is, to recover, you'd have to show that the show had some kind of culpability beyond negligence: like leaving the keys in the car, or leaving the car running and walking away. If they left your car in a bad neighborhood outside the shop's parking lot, that might qualify. But if all that happened was you parked the car there and someone broke in and damaged it, the shop is unfortunately not legally responsible. They do have to refund your money if they didn't make the repairs and you no longer need them due to the extent of the damage.
If you are able to find out who broke into the shop, you can sue that person for the cost of repairing any damage and the reduced value of the car due to their actions.
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