they claim to know but they are ***********

I took my car for a major service in the E car service in the menlyn branch Pretoria east in May, then in July my car started to show the engine oil light, it kept on lighting it and every time I check on the oil level the level was fine but when I checked the invoice I got from them and what I saw was that a wrong oil was used on my car I therefore took my car car and complaint so the took it in to drain out the wrong oil and put in the required one. The later also my engine performance started ging down then I took my car to the Bmw dealer then it was diagnosed and I was told that the wrong spark plugs had been used, There I bought the new set of spark plugs and put it inside then it was fine again I went to the e car service to complain then they did give me my money back. And now the person who was replacing the air filter on my car did not put the air filter holder in a correct way it touch the fan belt puller now the holder is damaged due it was not put properly. I went on the 10th of September to complaint but the workshop manager said he wont be able to assist me