Audi Umhlanga Broke a my car boot at a service, that was never broken when it went in

I took my car in for a routine service, because my car is still under warrantee and service plan as requested if the boot cover was still under warrantee as the rubbers has worn and was rattling. When I collected my car late the same day, I was amazed to find that the boot privacy cover was broken off and lying in my boot. This part was NEVER faulty and I Never asked anyone to do anything with it. I reported this to the service manager Steven, who phoned me telling me that he spoke to his technician and the car was broken when it arrived. THIS IS *******. I am extremely unhappy and want my car repaired to its original condition, I will not accept a broken part by Audi Umhlanga