Main screen isn't working

I accidentally dropped my phone while it was open and now there's two small pixels on the main screen and it wont let me use certain parts of the screen and randomly taps on apps. How do i get it fixed and through who? The small screen works perfectly fine but the main screen doesn't. They'res also some damage on the outside hinge, but i haven't even had it for a month. Im hoping its not that expensive of a fix