Terrible service at Hyundai Strydom park

I took my car for service on 17th of July FOR 60K major services, report came back saying my brakes are fine. a day after i started hearing some sound when I apply brakes, I have been taking my car there every week after , last time they tell me brakes are damages and I must buy new brakes, when I asked why because my car was fine when I took it there it had no problems, when I took my car it was still under service plan, been calling to speak to the service manager till today he has not called me back. why must I buy new ones where else a month ago my brakes were fine and if they had change them THEN OT DETECTED the problem we would not been here