Phone frozen and wont turn off

My samsung phone suddenly froze when i was opening snapchat, it wasnt uncommon so I waited a bit before trying to power it off to restart, it wont power off and has been stuck like this for 40 minutes. And when i went to my friend to ask for help she ripped off the screen. It still works but still is frozen, it is at 30 percent so it wont die for a while and i cant get the back off to look at the battery. It still vibrates when I get a call so I know it still works.