My iPhone 5 (iOS 7) has frozen on the lock screen. It will respond in the accessibility service button, but then I can't slide to turn off to restart my phone

So my phone is frozen on the lock screen. I tried to turn it off to restart but because it won't respond (it's frozen) it won't slide to turn off. For some reason it responds to the accessibility service button I have turned on because my lock button is broken, but then it won't do anything else so I don't know how to turn it off to restart. I tried holding down the lock and home buttons at the same time but that didn't do anything. I don't want to have to restore it to factory settings but I'm not sure what else to do other than maybe letting its battery die then turning it on again?