My phone displays a white main screen

Question

my phone has a blank white main screen and i don't know why the front screen still has everything on it but the main screen is white i have only had my phone for about a month and have not had a problem with it until now what should i do and how can i fix it?please help i just got my phone it has been 12 days since i had this phone but it got ran over and now the screen is white but everything else works please help me i love this phone