Car repaired with inferior paint and sold as new!

I bought my \brand new"Silver Renault Sandero Stepway in July 2012. To date the car has done 35000km and has gone for 2 services. Since December 2014 I noticed a bad discoloration of the Bonnet of the car and decided to take it to a local renault accredited panelbeater for a opinion. To my disgust I was informed that the car seemed to have been damaged and resprayed with a substandard paint with poor UV resistance. Once the clear guard of the paint diminished the paint had much greater sun exposure and started to discolor which means it took almost 2.5 years before the \""cover up work\"" became noticeable. I still have 3 years of installments left for this car and my local dealer wants me to negotiate with Renault SA who has been less than helpful to own up and take responsibility. According to their records the car was sent to the dealer without having any repairs done. Whether the repair happened after that with the courier company or even the dealer I wont know. All I know is that I got the car and paid full price for it but now have to face a declined warranty claim as no one wants take responsibility for the damage. I was told by Renault SA that I will be responsible. Not right"""