While playing the Android game Alto's Adventure on a Samsung S7 Edge, I had to watch an ad to revive my character, but then my phone got stuck. It is saying "Buffering" on an empty black screen instead of showing the ad. The phone has not responded to the power button (no matter how long I hold it for), it has not responded to the home button and it has not responded to the volume buttons.
I have tried Android Device Manager, but it is unable to locate my phone.
Technical details: Samsung Galaxy S7 Edge on Android Marshmallow
I just want to get my phone to respond and to work normally.
Any help is appreciated!