Appalling Service from Audi SA and Audi Rustenburg

I took my car in to Audi Rustenburg after hearing a weird knocking sound when I reverse and apply my brakes. They advised me that my engine mountings were worn out and after replacing them the noise would disappear, after replacement noise didn't disappear. I went back again they then said control arm bushes needed replacement, those were replaced but noise didn't go away. Took vehicle back, and now I'm told that Audi SA technicians advised them that once 'AUDI' vehicles reach 120000km they make noises. My first thought is I drive a 3.0 TDI Quattro, how can 120000km cause noises when people drive s****py cars that drive to 400000km, my immediate reaction is I WILL NEVER BUY OR ADVISE ANYONE TO BUY AN AUDI, if the people selling us these cars already have such little faith in them. AUDI SA has not come to the party to assist me as their customer. AUDI CENTRE RUSTENBURG is the worst dealership you can ever go to, their mechanics are clearly *********** and really do not know their job.