Renault little Falls

My Renault Duster's Engine and Stop lights started coming on. Been at Renault Little Falls three times as they could not detect the fault. The initial Service cost R14 that was supposed to have fixed the issue. They just cleared the alarms. My Engine started to show smoke on Startup this weekend. Mobile mechanics came out and did Advance Diagnostics on the car and pinpointed the issue to my Turbo. I now need to replace my Turbo as result of Renault's incompetence to have identified this with their diagnostics tools initially. This could have been prevented