Phone keeps ringing, but can't answer, unlock or re boot the phone

I have Samsung J7+ phone. It's been ringing for more than an hour now.( It's a Viber call, but now even without wifi or data it keeps ringing)
Screen does not respond for me to draw the unlock pattern.
Power off button does not respond.
In J7+ it is not possible to remove the battery.
Right now the batty is fully charged, so I just let it to ring till the battery drains.
Is there anything else I can do?

Welcome to Android Central! You can typically force a Samsung phone to power off by pressing and holding Power and Vol Down together for about 20 seconds.

Please register on this forum, which will allow you to engage in discussion more easily, as well as post images. https://forums.androidcentral.com/as...community.html