BAD SERRVICE AND NOT GETTING CAR FIXED FOR TWO WEEKS

Hi Volkswagen South Africa, My name is Anthony i recently purchase an Golf 7 it still have an active warranty plan by Volkswagen, My car went to the dealership on the 13 of July as the gearbox had to get a clutch replacement , The dealership called me on the 25 that my car is all fixed and ready for collection, So i fetch the car i traveled 5 KM and then the gearbox didn't get reverse and say the car is in amercing mode so it does not get reverse gear and when you move it in park there is an big clapping sound that was there never before.