Iphone 6 plus screen won't work

I have a iphone 6 plus, it is about 2 weeks old and no damage at all. i was using it.. put it on the table to go to the toilet.. come back picked it up and there was weird white lines ( kind of look like thin boxes) moving down at the top of my screen. tried my screen and nothing.. all the buttons work fine just not the screen ??? I am pretty angry as i have taken good care of the phone and there has been no pressure on it at all and has been kept in a case.. the nearest apple store is a city away

Anyone have any ideas ?? i live in the uk and have a 16gb space grey... tried to reset it threw iTunes and now cannot get past the first screen