Audi SA its not useful as its supposed to

Bought a new Q5 at audi centre Northcliff end April 2018, just when i got the car i found out that they fitted a A4 ****pit in a Q5....they said its a factory fault they'll tell Audi SA and get a Q5 software to install, agreed and drove of, the next day when trying to use a cruize control, its not working, notified Audi SA which advised me to take the car back to the dealer as ig has a factory fault.

The Sales manager insisted that he'll fix the car as soon as the ****pit arrives, i told him i dont want a fixed car, get me another car or lets cancel the deal. He agreed of getting me a new car, after few days without hearing from him, i called and asked about the findings on the new car. He then there is nothing wrong with the purchased car, he'll fix the as he cant find me a new car. I said i dont want a fixed car. I then shop around to get myself another car as he said he cant find one, i discovered that the car he sold me that its a new factory fitted car, its actually a aftermarket fitted car. I then went back telling the manager that, i don't want to continue with this deal anymore as you **** to me and give me a aftermarket car telling me its a factory fitted car. He then say he cant deal with me, i must now soeak with Dealer Principle, who didn't want to even solve the Matter of false sales information but continued and take the managers side and say no cancellation of a deal. I asked him if the aftermarket has warranty cover, he failed to answer me. Audi SA came back to me after its consultation with Northcliff, and i asked them if an aftermarket fitment has warranty,they sais NO, but they told me Northcliff say theyll di the fitment as soon as the part its here. When i ask them who wm be liable to the warranty, they fail to answer to, but they say they there to assist us. What is the use of Audi SA as they allow the dealers to badname the AUDI brand? Audi SA you failing us, you allowing this dealerships to drag your name in the mud.