iPhone 5 Screen goes black and none of the buttons are working

My wife's Iphone 5, a few weeks ago the screen would shut off and restart. the power button on top started having problems working and she would have to press down on one side of it hard to make it work. Today it went black and would not come back on. None of the buttons would work the side switch would not work. When I plugged the earphones in the in-line controls did not work either. Calls would be received and the phone vibrates but we can not actually answer the calls. After a couple hours, the screen just came on. It is the white screen with the apple logo, this screen will not go away. I've tried holding down the power and home buttons simultaneously for up to 30 seconds.