A:Answer The best thing to do is to take it into the store, and they will handle it, from there. There is a chance that they may not be able to fix it (depending on the Brand and Model Number) so I would make sure that you backup any data (I use Google, so it is easy) and clear it from your phone (if possible... scratched screen).
In my case, they issued me a store credit, which I used to purchase a different one, which I had looked at a month before, and had a lowered price, since then.