My iPad mini 2 is frozen and won't turn off

Hi.

I have an iPad mini 2. I've had it for a year now and is in good condition. I was on my iPad just on facebook messenger, when it froze. I can't press the home button and get to the menu, neither can I turn it off. The only thing I can make it do is sleep, and when I do wake it up, it is still stuck on messenger. I need help here so I can get my iPad back to the state that it has been. Is there anyone who has been in the same situation who knows how to get out of it? Please answer, because I really want it back to normal.