red smudge like spots/patches have appeared on my ipad 9 screen

Red smudge like spots/patches have appeared on my ipad 9 screen randomly one evening. It is still covered under warranty and i have submitted my ipad to apple service centre but they are refusing to cover it under warranty and even refusing to check the device.

I live in jammu ,J&K, India.

Since it's been around a month I have submitted my ipad and have gone to service center 4-5 times and contacted apple support around 7-8 times.

I am a student and most of my studies rely on Ipad and it has been very inconvenient for me since my ipad is gone.

Kindly contact me and give support as soon as possible.