Renault cleo engine fault

I booked my Renault cleo for 180000km major service, the car broke down I towed it in the renault service Centre centurion and told them that the car is not starting. They indicated that timing chain might have been damaged, because I skipped the previous service interval. they indicated that to check the car and confirm it will cost me R5000, I didn't have that money at the time. They told me that they cant service the car without diagnostics and solving the problem. I went to carnetics cc in centurion who checked the car for R2800, and indicated that if I fix the car with them they will omit the diagnostics cost. I instructed them to fix the car and the cost was around R35 000. Then I took the car for major service at renault centurion with my service plan, i.e. Liquid capital. They reported that the car was fixed correctly by carnetic, except that the timming chain was not done properly. I took the car back to carnetics who claimed that they used genuine timming chain and they use special equipment to time it and its accurate, they took the car in and fixed it the power was better but not same as original and the engine vibrates when on idle, I was told to drive it for a week and come back. I took it back to carnetics after a week and seeing the engine light is on they took it and fixed it again. This time I did not get a report on the car after 2 day it says The error message states 'check injectors and exhaust system. I was hesitant to drive it I called Michanic mobile mechanic, they did manual diagnostic on the car and confirmed that injectors are ok I must go to others for checking exhaust system. Max panel beaters confirmed that the exhaust system and catalytic is in order. I am trying to sell the car as is, and I am not getting value back. I do not have money to fix this car anymore. I was advised again that the timing chain might be the problem and that at 180000km service Renault was supposed to do major service and change the timing chain as well during major service. I need expert advice on the matter. i will appreciate any advises.

Regard Jossy