Deceptive and unfair business practice

We bought a vehicle From bbnissan sinoville 2017. It was a second hand vehicle and we were told that the is vehicle and all Other wear tear parts were replaced and new. Not so long after we had bought it within the first 2 months the breaks were making a whistling sound and we took the car in to the dealership. They then returned to us and said it was "dust" that was making the breaks whistle and they had cleaned them. Within 2 weeks they were whistling again an we went back. They said the same and did the same thing they did the last time. But all they really did was tighten the breaks. Another week or 2 passed the same problem came back. 6 months later Now at a new service centre i am told that the breaks are severly worn out and as a result have damaged the break disc and everything had to be replaced. This vehicle is not even a year old and i believe it was sold to me with used brakes. The salesman Mr Viking Mabasa has not been truthful to me throughout and i feel hard done having to pay ridiculous amounts of money to replace something i had been told is new. I asked for a way forward and all i got was "its not my fault its the workshop" as if the workshop is not the same company. To anyone who wants to buy a used car... DO NOT GO TO BB GROUP NISSAN SINOVILLE!!