Iphone 13 pro - display brightness issue

I bought 2 iphone 13 pro (hongkong specs) On one of the phone i noticed brightness is quet low even outdoors. Auto brightness is OFF. When I compared with my other 13pro phone by keeping the brightness levels at completely low the affected phone is more darker than the other. And its a brand new phone. I went to apple store they reinstalled IOS but its still the same. The phone should be replaced but im not getting any help from APPLE ! Sold me faulty phone and not replacing it! What can be done?