12k Fuel Pump missing after handing Car over, Audi simply doesnt know where it is

Rejected a quote from Audi Centre Port Elizabeth "they had prior done alot of work" Parts and vehicle were handed over to another company to bore the motor , Fuel pump went missing , Gareth Claims they gave all the parts back in one, then when questioned gets caught out , parts were given back in pieces, also complained my engine cover was missing , last time I had to buy a new one, and Audi also said its not them, the car had not been anywhere else, Now I am a engine cover short, and a 12k fuel pump because they simply, do not know where it is , shocking service and dodging responsibility