You have to give the dealer a chance to rectify the fault, in this case look at the clutch and sort it by adjustment of the clutch cable (be it cable or hydraulic) or it might be needing a new clutch plate, thrust bearing, etc if they are faulty.
If after that you still have the same problem then you can give notice of rejection.But i don't think it will come to that as fixing a dodgy clutch or at worse replacing it with a new one, should be straight forward.