Volkswagen T-Cross poor paintwork

I purchased a new white T-Cross 1.0 TSI 85kw in 2022 for R424 775. The vehicle has done16 700 km and is like new. Recently a yellow coloring has emerged in the rear right hand door edge, which has moved to the inside edge of the door as well on the door post and on the inside edge of the driver's door. I have advised VWSA of the problem, as well as the dealership from whom I purchased the vehicle, Bidvest McCarthy Menlyn. I have travelled to various locations to have the vehicle inspected as requested by VWSA. All to no avail as VWSA and the dealership do not wish to take responsibility and or are unable or unwilling to offer any solution for the poor paintwork, and I am left with the resultant loss of value.