Audi Q5 S-tronic Gearbox Failure

In August 2019 we purchased a used audi Q5 2.0 tdi s-tronic from audi claremont in Cape Town. The vehicle seemed perfect until December 2019 when we wanted to travel and the vehicle started with squealing noises from the alternator pulley, audi claremont diagnosed no fault. While travelling in December the silver plastic surround of the driver air vent broke, when travelling back both sliders for the driver and passenger air vent just exploded in our hands when using them. We also noticed the lighting of the rev counter lights started flickering on and off occasionally. In the beginning of January 2020 the egr cooler failed. I took the vehicle back to the dealer to repair and they only were willing to cover costs of the repair of the egr cooler, I was quoted R2650 per air vent to replace, to which I refused, I did not even bother to listen to the costs of the other repairs they were not willing to cover. Upon receiving the vehicle back from being repaired I traveled from Cape Town to Worcester for work with two of my colleagues. While driving the plastic ***ling underneath the engine came loose at 120kph on the highway, scary situation. The reason for this was that six of the nine hex *****s holding it in place were missing. Now not amused I returned the vehicle to the dealer for a solution, I was again given a quote with an outrageous amount. I then emailed the dealer principal for a solution because as per the CPA they are obliged to repair or replace any reasonable fault within six months of purchase. They eventually comp**** with this. When delivering the vehicle for the new repairs the egr cooler actually failed again when starting the vehicle to drive it to audi claremont. When at the dealership the service advisor inspected my vehicle and advised my spare wheel electric pump was missing too. This vehicle was so poorly inspected before we took delivery of it in 2019, missing spare wheel pump, missing *****s. Now in May 2020 my s-tronic gearbox has failed to which audi claremont has refused to repair. Every one of these faults have occurred within eight months and 15000km of us owing the vehicle. This vehicle has had a full service history with audi including the correct gearbox services maintained, and travels approximately 50kms per day driven by my wife. How is it possible that a vehicle of this high caliber that is correctly serviced continuously has major failures within such a short frame of time. Audi sa refuse to step in and have told me that they cannot tell audi claremont, a dealer, what to do. How am I incorrect by demanding audi claremont repair my gearbox at their cost, they have clearly sold a defective vehicle and refuse to knowledge this.