I dropped off my vehicle to have the rear bumper replaced

I dropped off my vehicle to have the rear bumper replaced. After a few weeks I collected the vehicle and realised that the paint job on the bumper was really bad They had painted over the lines between the black and where the paint was supposed to end. When I got home I also realised that I could no longer lock my car. After back and forth between the paint job and the locking, they sent the vehicle to Mazda. Mazda replaced the central locking control unit as their tests said that an over surge in jump starting the car did this. The car definitely went through something as all my settings reset to default when I fetched the car. The branch basically called me a **** and that the central locking didn’t come up on their diagnostics. It wouldn’t by default. Mazda had supp**** the report and I was email and told that this job was closed and their is no further action. The facility has surveillance cameras and when I asked for these to be checked to confirm that my car locked when I dropped it off was completely ignored. It is rather disappointing to be treated like a number. I will continue to escalate this to the insurance board and Ombudsman. That branch should not be in business based on their total careless and shocking customer experience.