Bad service

I took my car in for a service in May, I was told my brake pads had to be replaced and they were. When I took the car home it was making noises that it did not have when I took it there. I took it back the following morning and I was told that the brake pads they had installed had a fault and they would replace them. My car was still making the noises and I was told that I could drive it, but not over 120km/h. I have done that and I hardly drive the car, but the noises have just gotten worse. When I call, I am told they are still waiting for parts. I am afraid that it will break down at anytime. The service manager is not helpful at all and is extremely condescending,I don't know I'd that is die to the fact that I am a black female. I even contacted the sales person that helped me buy the car and I have not received any assistance.