Same thing is happening here with the volume and now the icon is stuck on the screen. It goes away when I manually press the side switches but instantly fights with me to go back up and reappear. I've only had the iPad for a month and my kids mostly use it to watch videos on so the volume suddenly blaring is an issue. Assume both you guys took it back to the shop. Will give apple a call and do the same, I imagine. You can't even mute... It overrides the mute switch! And in the settings any volume button moves on its own wherever on the screen - in the double click the button one, in the settings, restrictions etc. very frustrating!
Brookot--along with all the info gathered here, have you tried to do some of the immediate fixes. I didn't see that you mentioned that you tried the following...but give it a try as well.
Have you tried to do the following?
1. Force the app to close?
2. Try to restart your iPad?
3. Try to do a reset?
You can try this in order, if an app becomes misbehaves...
Force the app to close down by pushing the home button twice or by doing a 4-finger swipe to bring up your multi-task bar. This will show all the apps that you have visited. Press the app, until it begins to shake. Close out the apps by pressing the red circle in each app. It will only quit the app and not delete. Than try to re-open the app and test out.
If that doesn't work, restart the iPad by pressing the power switch down to power off.
Third is to do a reset by holding the power switch and home button together until you see the apple logo. Hope that helps!
Skimonkey ~~ sent from my iPad MINI using iPF