Pixel blow on OLED screen to my new Iphone X

My iphone X’s screen become like this (see picture) after I leave it to charge overnight. How can this be possible? To make things from bad to worse, Apple Service Centre told me this is not covered under warranty because this might due to excessive pressure put on the screen. I’ve shown the advisor the phone’s exterior condition that was perfectly new without even a single scratch, I’m even using original apple leather case, with tempered glass screen protector..I hope Apple will reconsider my repair application..#sigh

Requesting thought/ suggestion among communities regarding your experience dealing with apple warranty service. Thank You.