I want to file a legal complaints against Hyundai...

I want to file a legal complaints against Hyundai Service Center because twice I almost got died due to engine failure. I had all my car servicing through Hyundai Service Center. I purchased it as a brandnew car last 2013. Last June I experienced engine shut down while driving at a speed of 140kph then I paid for the repair of the short engine with them. The day I took my car after they repaired the engine I experienced some strange thing of my car. One is the cruise control is not maintining on the desired speed I set and second if the car is on stop while on the stop light once it will run i always experiencing skidding. Last Friday I got an accident and its my fault because from stop light I experienced skidding again and my car went to left side which i cant control and the car behind me hit my car.