Just make sure you get on to them quick. The onus is on companies nowadays to not hold personal information for what is deemed 'longer than required' so it could easily be deleted in a few days if the retailer operates that way. But gutted for you, its my one big fear - also agree its plausible it was deliberate but could easily have been an elderly person who slipped as exiting the car and leant the door against it, or a younger child, or even someone who walked around the car to open the door, it was frozen shut, so gave it a tug and...
Either way if you can get video evidence and a number plate you are quids in.