Renault defect?

My Renault Captur has picked up an intermittent shudder when taking off. I raised this with Renault on my previous service (a year ago) and was told that it was not a problem. I raised it again when serviced recently and was told that the clutch needed replacing. My car is still under warranty and is only 3 years old so I requested it to be covered under warranty. They are now trying to tell me that this is normal wear and tear! Mileage is low and the car is like new.

My view is either the clutch is not damaged and I have called their bluff, or they are skirting their responsibility.