Iphone6s Third-Party MDM restrictions needed

I installed a Third-Party MDM app/software called Qustodio on my son's iPhone6s to monitor and control his internet, texting, and app usage; etc. As of right now, he could just go into Settings>General>VPN and uninstall this program; making it essentially useless. Is there any way I can restrict him from altering the VPN / MDM settings or deleting it all together? Haven't been able to find anything useful on the third-party site other than a reference to Apple Configuration2 but resetting the phone to factory settings was mentioned if I try that route. Any and all assistance will be greatly appreciated.