New MacAir 2020 Discolouration -

Have a new MacAir machine bought in March 2020 - dark grey and during lockdown it was not used as I used my Mac PC and now it has discolouration on the right side of the keyboard and when I went iStore Fourways it is said they cannot help me and discolouration is not part of their problem or covered under warranty!! When you pay almost R30k for a new machine and the colour changes only on one side to now almost rose gold you expect more from Apple (iStore) - how is this acceptable? It looks terrible and reflects bad on Mac as my machine looks like a cheap import which it certainly is not and bought from iStore Sandton!