Bad service and poor management

I would like to put a complaint and dissappointment about the service of ACX Bosch in Pietermaritzburg , i took my car in last year August for clutch but my car out overheating and i heard consined about that try to understand how possible is that and i had to fix that cyclinder head was done by them and when i wrnt to pick up the vehicle still showing sign of overheating and they said i must change oil cooler was leaking and it was changed but no change on my car and the mechanic said i must change the water bottle they keep on guessing and i change the water bottle because am fighting with them and i don't want my car with them within a month the car was mixing oil and water and i took it back to them and water make me laugh they reject my claim because i change the water bottle myself not them , they said i should bring the car to them to change it for me since then my car was not right even now