Bad driving or Weak quality material?

I bought a 2014 Opel Astra Essentia Hatchback model in September 2015 and in less than a year a, I mean in May 2015, mind you i was not driving the car from Feb -April 2015, the clutch starts shuddering after its 21000km on the clock I took it back where I bought the car and several other dealers. I complained about the clutch shuddering I was told it was my fault and I am to pay -+R20000.00 to replace the clutch. After complaining to Fury GM in Rivonia and I told them to sell the car and i am not bound to pay -+R20000 to repair it. Although I have driven the car for less than a year and costing me -+R200000.00. To me who has been a admirer of Opel, Chevrolet and Isuzu owner over the past 10 years this is a low blow to have a car Opel Astra Essentia hatcback clutch giving in such a short space of time. clearly this shows of weak quality material used and fitted parts which GMSA won't admit to.They always do this to customers after you buying a car. You become a good customer and get a good service before buying a car afterwards its your problem not theirs.