Sorry, but there isn't any way to stop them from removing a profile installed via AC2 for 30 days. After 30 days it does (supposedly) become permanent. This is an Apple restriction and not an MDM restriction. The idea is that it prevents a nefarious actor from taking control of a device through an MDM profile.
If you're having issues with the profiles being removed, try using loss of access to wi-fi as a deterrent. Or some other positive or negative reward for leaving it alone. That said, I 100% guarantee that a few students will still remove the profile and try to hack the system. It's the nature of the beast. Only thing you can do is try to stay ahead of them. Monitor and manage.
Good luck!
Greg Bobbett
