The fact that they sent it off without notifying you is shady, it makes it look like they were (are) trying to cover something up. Usually shops let you know every step of the way if things are being done (or need to be done) beyond the work that you hired them for.

You need to do everything that Ferdman mentioned.

Has the body work started on the vehicle, if it has not started or even if it just started you need to get over there with a camera and photograph everything.