My iphone13 pro max display is not working

Hi,

I bought iphone13 pro max one month before and now display is not working. I have been taking care of this phone never before.

I tried hard reset , Draining of the battery and also tried to recharge without actually off the display options. Still its not working and Iphone service center is also not looking into the issue seriously. Its been 8 days I submitted the phone still no response. Can some one help me.