It's clear to me that Renault dealers know precious little about these cars and even less about customer service. As far as I can see, they are seemingly using 'normal' vehicle tools and processes to measure the thickness of the discs and therefore coming to the conclusion that the discs are almost totally worn out. I doubt that is the case and the same happened to me.
The issue I believe is that the cars run pretty effective regen 'neutral' braking upon lift-off and therefore we don't need to use the brakes very hard. They rarely get a proper clean up and therefore corrode, which causes the noises and the reported binding. And of course foot-braking also leverages a heap of regen, further adding to our problems.
If you are a PowerBox user, then a really easy way to clean up the discs is to switch off Neutral Regen Braking (ie: lift-off / overrun), reduce the Foot-Braking Regen to 0% and then go for a spirited drive for a few miles until the brakes are nice and shiny once again. This method will ensure that only the hydraulics and your leg power is used to slow the car and everything will benefit from this 'Italian Tune-Up"! Once everything is cooled, have a quick inspection and if it still needs more, consider running like this for a week or so. Then switch Regen back on and job's a good'un.
If you've not got a PowerBox, then I'm afraid you will simply have to use the brakes very hard on a quiet road or journey early in the morning until the discs clean up. The effect will be the same, but without a PB you won't be able to remove the regen effect which of course does most of the braking in normal driving. You may have to be a little more brutal.
BUT - before doing either of these clean-up techniques, please check that your brake pads are in good shape, as these also start pretty 'thin' and if they're not in the best of health, get them replaced, An easy job for a sensible home mechanic and could be completed within the hour probably, both front and back. Then bed the brakes in carefully before going for the clean-up process proper.