OnePlus India — Pink/Green Line on my one plus 8T

Address:

111 Barakha Road TNHB Colony Kilpauk

I visited nearby OnePlus service center to resolve the issue but they said that the issue can be fixed by changing the screen of the phone with free of costs but it should not have any physical damage.
And so The OnePlus service center didnt accept my mobile saying that my mobile have a minor scratch mark nead slider button, (screenshot also attached).
So now the situation is that, only if I pay 14k for the screen change then this red line issue will be fixed.
But it's quite clear that this issue is because of the latest OS updates or some hardware issue caused by the update, which has to address by OnePlus Team themselves at free of cost.