If you think, your Renault has a serious defect that affects the safety of the vehicle, report it to the Renault Dealer immediately. If you’re not happy with how the Renault Dealer is dealing with your report, in the UK you should contact the Driver and Vehicle Standards Agency (DVSA).
But before that, you can describe the fault of your Renault in our forum. Maybe some other Renault owner will learn that he experienced the same issue. Multiple occurrences of identical defects mean a better chance of success in a complaint filed with the DVSA. Our website is visited by Renault owners from all over the world.