Script to block ALL VPN connections

Hi...
I am using Shibby Tomato v132. I have "Intercept DNS port
(UDP 53)" checked. - -

Is there a script or anything I can do to block internet connection to users using vpn plugins like DotVPN from Chrome?

I use OpenDns to block porn, but I noticed that if the Chrome plugin DotVPN is installed, it bypasses any and all settings on the router and the user can access any website.

Is there anything I can do to block these type of connections? - please help, thank you.