Mercedes Benz seat tearing in stiching..

Good day I purchased my Mercedes C180 AMG line, in December 2018 , as a demo vehicle with only10000 km on the clock ,when I was medically boarded , and as my retirement vehicle(6 months old and the remainder if the 6 year factory warrenty) .I officially retired 09/02/1923. After 4 and half years of ownership my driver seat start tearing in the stiching and the headrest showed signs of cracking, which to me is clearly the quality if material used) After complaining on various platforms,eg : Dealership (Culemborg Cape Town (21/02/2023), Mercedes customer care 03/03/2023,ref no: ***9(no response to date) and finally Mercedes Benz South Africa head office (24/03/2023),I was informed that they are only prepare to cover half of the repair cost as the interior of the vehicle is only covered for 2 years(my contribution would be approximately R7000 as they stated). I found this unexceptable for a brand of this vehicle to use such inferior quality materials for their vehicles and for it to start falling apart at such an early stage.I send them pictures of the damaged seat as well. As retired person I feel this is unnecessary expenses I have to fork out now. Mercedes Benz SA should realy be ashamed of themselves to for the inferior cost saving materials they using in their product.My passenger seat is seldom use and the rear one are hardly used (just makes me wonder what the condition would have been if it was use as often as the driver seat .)I am the only drver of this vehicle and weighs only 65kg.I am hugely dissapointed in choosing this luxury Mercedes as my retirement vehicle.....