BMW Rustenburg

I took my BMW 116i to the legacy BMW in Rustenburg on the 22 February 2019 for service and Saturday the car would increase speed due to drive train. Alright fine then I paid for drive train which apparently was the injector. On 30th April 2019 drive train shows again n again I can only drive it 40km/h. It was towed to Rustenburg again and no the car was there for more than a week when I went to get car on 20May 2019 the invoice was exactly the same as Feb2019 so I refused to pay until the service manager reduced the price. Eventually they agreed to reduce. On the 28th May my husband drive to go to Dr and the car breaks down with same issue. BMW Rustenburg made us pay for fixing the issue that was supposed to fix 8th of May. I got tired of fighting so I paid n sold the car on 29th May.