Why isnt my Samsung Galaxy tab 2 responding and frozen.

My Samsung Galaxy Tablet 2 has been frozen since 11:00 and its 07:01 right now. I've tried to press and hold the power button from 10-17 Seconds but nothing happens....even tried holding down the power and the volume up button 2 times for 10 seconds!! Nothing happens. Should i wait till its charge runs out. it was 88%?

I dont know what to do...my parents are gonna be pretty angry..