Iphone frozen after accidental hit

So what happened its that my iPhone 6s plus last Monday get hiited while exercising I thought its was just a screen replacement because the phone background automactilly get white and every app letter get on white also every time I try to open any app the phone reboot I though its was something of electricity due to the crashed screen .. so I get the screen replaced but the problem still happening the phone its all white unless the apps logos and battery colors .. what its happening ?