Dropped iphone 4s and the screen is now grey with black corners?

It wasn't even a hard drop.honestly i do drop my phone kinda often but i didn't have a case on this time. My screen didn't crack. At first it was all grey and now it has black corners. I've tried turning it off and charging it nothing changes.anyone seen this before/ know what to do?

Added (1). Please SOMEONE Help ME

Well then send it to apple

There may be something wrong with the LCD flex cabel, which means you have replace the lcd display.