Bad service at Rand rover center

October 2020 I took my car to Rand Rover Center in Randburg, I used a tow truck because my car was not moving, they quoted me R89000 and said my car will be 100% OK in 3 weeks time, December 2020 my car was still with them, January 2021 they give me the car and the next day I realized that it is leaking oil and it has a problem when accelerating, I took it back. They returned a car and this time around it will just switch off while driving... I took it back again and when they returned it, it was still leaking and the accelerator was still a problem. Now when I take it back they want me to pay another money for them to fix it. My car was never OK since I paid R89000 not even for a week or few days! I'm really disappointed at the service received at Rand Rover Center because in my understanding, they're supposed to test the car before calling me to pick it up, but I'm the one who always finds fault when I drive it home. Everytime I take it back I'm told to pay more money though the agreement was that the car will be fully functional after paying R89000. I've complained to the management on several occasions but nothing has been done to date.