Repairing to Mercedez injectors - car break down

We took our car to Viljoen Motors on 23/06/15 for the fault on the vehicle not starting when warm.Isak informed us that the injectors is faulty and needs to be repaired which will cost us R15750,which we agreed on and paid a deposit of R10000.On 3 Jun Isak informed us to collect the vehicle (we from Fochville) we collect the vehicle and on our way home we had to stop the car due to a hard noise in the engine phone him and ask what we should do as he rep**** that he will not be able to assist as we are already to far but will phone someone to assist.He rep**** we should drive with the car in that state to Carletonville where a friend will fix the problem.We left the car at Carletonville to collect it the next day.Next day collect the car and the man insured that the car is good, the problem was solved one of the injectors was not properly *****ed tight.This was all done on the 4th.Not once did Isak Viljoen phoned to make sure that the car was fine, I phoned him. 5/06 to Palaborwa and on Saterday the car left us next to the road with the one injector through the cover and diesel all over. phone Isak and he rep**** that it is our problem.I had to get help a further R6747.17