Can't turn off tablet, need to so I can hard reset. (Unresponsive touch screen)

[AC Question]

I have a Gigaset QV830, the touch screen became unresponsive recently...
But it seems that if I want to turn it completely off, I have to press power off on the screen. I wanted to hard reset it, but can't since it won't power down.
I tried to press volume up & power at the same time... It just restarts itself.
I'm attempting to usb debug it as well, but of course that's not enabled, so I'm at a lost of what to do about this.

 

[chanchan05]

Wait for it to run out of battery then plug it in and wait for a full charge without turning it on.

 

[B. Diddy]

Welcome to Android Central! On most Android devices, pressing and holding Power for about 10-15 seconds will force a shutdown. (On Samsung devices, it's Power and Vol Down together.)