Unfortunately I used a bad VPN service called VPN OneClick Pro. When you uninstall the app it does not remove the VPN configuration files it creates in Network in System Preferences.
So in other words, when you open System Preferences and then click on Network, to your left you always see your Wi-Fi, Ethernet, Firewire, etc. VPN OneClick Pro places about 28 VPN Configuration files. The minus button "-" has been greyed out so removing them is impossible.
How do I remove the remnants ?