EM Service Centre in Edgemead - Trial and Error Resulting in HUGE Cost and Car Not Fixed

My car was in limp mode. The guys from EM Service Centre in Edgemead Cape Town kept my car at their workshop and went through a process of trial and error, replacing parts as they went along. The cost of the "repair" built up to over R14000, and the car was still in limp mode. I asked them to put all my old parts back and refund my money, but they would not do that. I had asked them for all my old parts to be returned, but only one part was returned. I believe that they disconnected my car's aircon to "resolve" the problem. My car was returned with absolutely no petrol in the tank - the red light was on. I have no idea where they went with the car to use up all the petrol, there was at least a quarter tank of petrol in when they received the car. It is going now, but I have no aircon, and the cost was R14011.60. I now need to take my car elsewhere to figure out what the actual problem is and to sort it out so that the car runs properly with the aircon connected. I will NEVER return to EM Service Centre. Holger, the main guy there (I think that he is the owner of the business) does not know what he is doing. Trying to fix a car by trial and error and building up a huge cost in the process is not the way to go about sorting out car problems. I do not even trust that all the parts they said were replaced were actually replaced.