Regret ever doing business with them

My Mercedes Benz vehicle has been there for months and I thought they would've done a great job on my engine but little did I know that they were damaging my car to be in a worse state, for a company that is RMI-approved I would never recommend anyone to take their personal vehicle there for repairs. When I received the vehicle I was told that the performance was great however when I collected my vehicle and took it to Mercedes cause now I got the car back with an Engine Light on, Oil Leaks, Engine cooling fan constantly on even when opening the door and ofcause the performance was terrible. Mercedes inspected the car and I was shocked by their findings, Timing is completely off hence it never had power, the timing chain guides were grinded and altered to fit my car cause it wasn't a Mercedes chain guide, and the threads on the engine mount were *****ed in with a wire so the bolt could ***** in and many more unprofessional works man issues were found costing me an additional R32K to fix now. I honestly regret ever doing business with them cause as a client I was even sworn at for asking for updates on my vehicle and weekly I had to always request feedback. with all the money gone and wasted, I hope this never has to happen to anyone else in the future.