Home and Lock button doesn't work after deleting things in settings

My iPad mini isn't responding when i press the Lock button or the Home button. Before this happened, I was deleting things out of my memory in the Settings app.

When I deleted my Facebook app (I was trying to update it as the rest of my iPad had updated ie Youtube, Snapchat, etc etc.) it took me back to the main settings screen, thinking that I had deleted it. I then proceeded to go back to the home screen, after I pushed the 'home' button, nothing happened. I tried it several times. I then tried the 'lock' button, but to no avail, it didn't do anything. I held the power button down for several seconds, nothing happened then again for a minute. nothing happened. I didn't want my iPad to lock in-case i couldn't get back onto it.

I have also tried the assist touch, it doesn't work when i press 'Home', 'Lock' or anything similar.

In short neither Home or Lock work.

I've had the iPad mini since Christmas 2012.

I am currently restoring it back to factory default setting to see if that fixes it.