POOR CUSTOMER SERVICE & CLUELESS

I took my BMW E90 to Car Care Clinic Centurion because of disturbing sound coming from the suspension March 2015. I was told to replace control bushes which they replaced same day. Two months later the sound started again. I took the car back to them and I was told that the bushes are faulty and they will replace them with the new one because of their Six Month Guarantee/warranty policy. Till today my car is still doing the same noise and I took the car to them to fix this noise six times already. I went to BMW last week Friday for help and they advised me that I must fit the whole control arm in the car than just the bushes. This morning I went to Car Care clinic for the 7 time and requested them to fit the whole arm as per advise from BMW. I showed them the quote of the whole control arm which was somehow cheaper than what they charged me for the bushes. About 30 minutes ago i phoned them and the manager told me lot of nonsense that is irrelevant to my request. MY REQUEST IS TO FIT THE WHOLE CONTROL ARM IN THE CAR RATHER THAN BUSHES BECAUSE THEY FAILED TO FIT THEM CORRECTLY AS PER ADVISE FROM BMW