Xioami - Mi declared the product out of warranty

Purchasing a Xiaomi flagship devices was a very bad experience for me which caused me a lot of mental trauma
I purchased a Mi notebook ultra from a mi retailer. Due to any reasons a minor dent appeared on the laptop by me accidentally,
After * months of using this laptop i discovered some display issues of dead struck pixels which just suddenly appeared after normal usage which can be a manufacturing defect of the display .
But due to that minor dent when i visited the service centre with my device . They just declared the device out of warranty due to that dent on the device which was no far related to the problem i was experiencing so they just said to replace the screen and demanded the following charges for that.
This is really unfair as no issue was developed on the screen due to dent which was confirmed by technician .Still the company claimed it out of warranty and was not ready to change the screen under the warranty.
I have a very bad experience and a lot of travel charges along with mental trauma dealing with it. I will definitely file a report as this is not fair which happened to me .