tell application "System Events"
    tell current location of network preferences
        if exists service "Displayed Name" then
            set VPNservice to service "Displayed Name"
            if connected of first configuration of VPNservice then
                disconnect VPNservice
            else
                connect VPNservice
            end if
        else
            display alert "Could not find VPN connection"
        end if
    end tell
end tell

open "/Applications/Utilities/Toggle VPN.app"

osascript "/path/to/Toggle VPN.scpt"