Renault Megane GT

I bought a Renault GT Megane brand new in May 2018.After one week I washed the car and noticed that the car had unfinished paint sprayed on the bonnet area.I returned the vehicle at Renault Witbank and showed the manager but he said that there was nothing wrong with the vehicle and failed to assist me . I took the car to a approved panel beater to inspect the area he confirmed that the bonnet was sprayed over there was even blue paint on small parts of engine.I tried phoning Renault SA to launch a complaint but I was directed to different channels and no one was able to assist me with my query. This is very unacceptable service I bought the vehicle cash and I just want an exchange I don't want my money back I am a pensioner and it is very difficult for me to drive up and down to get assistance I am very disappointed in the brand!