Uneven surface of screen

I purchased i phone 7 last month after few days i saw a black small don inside the screen , i rush to authorised service provider at unicorn viman nagar pune !! They admitted my phone for screen replacement under warranty . After 5-6 days my phone was ready to deliver to me !! I took phone from them and gone for installing glass protector on the screen but i seem the all edges of glass protector is not sticking well on screen it having bubbles for all edges of the protector !! I replace the 10 protector of verious companies but the same issue is there.. also i put the same protector on my frds iphone 7 it stick well on the screen in first attempt on my frds phone !!! So the local accessory shop tech person told my phones screen is uneven !!!

I am realizing apple service provider has put local or faulty screen to my phone under warranty !!! Pls help me out for the issue !!!