Sounds like the screen isn't aligned quite right. Was this a new phone when you bought it? Because it sounds like someone attempted a repair and didn't know how to align the screen when they replaced it.
If its a brand new phone, take it to the Apple store and have them swap it. I wouldn't accept a brand new phone with such a huge QC issue. If it was used, follow the iFixit guide on removing the display. Make sure there isn't any debris on the battery or logic board. The usual cause of this is a random screw or something preventing the display from sitting properly. Also inspect the battery to make sure its not bloated. LiPo batteries can and will swell and then explode.
If everything looks ok, put the display back on. Put the top edge in first, sliding it under tab that holds it in place. Once you have the top where it should be, gently press your way down from the top to the bottom. The bottom should stick up about a MM, tightening the screws will pull that down into place.