I'm not an expert at this, but I see no one has answered your questions so I'll tell you how it works for me.
I use a for-pay VPN and it works perfectly with the settings below. One thing you didn't mention is if you installed OpenVPN. That might be something you want to try. Here are the instructions on how to setup a VPN in 12.04/14.04 according to my VPN provider (I followed these to the letter and it connected just fine the first time and every time since).
Open a Terminal, and run: sudo apt-get install openvpn network-manager-openvpn network-manager-openvpn-gnome. This will prompt for both your password, and a Y/n answer, please provide it with your password, and Y
Once installed, open System Settings, then Network. Press the + symbol to add a new connection, and select the VPN Interface, then press Create. Choose OpenVPN as your VPN Connection Type, and press Create
The following will walk you though all configuration steps needed for the VPN.
Gateway: Select one of the Hostnames provided on the Network page
Authentication Type: Password
Username: The username provided with your account
Password: The password provided with your account
CA Certificate: Extract the ca.crt file to somewhere it won't be deleted. We suggest your Home folder. If you extract this to your home folder, when searching for it, please click on your username on the left side, which will take you right to the home folder, then select the ca.crt file from the options on the right.
Advanced: Under the general tab, check the Use LZO data compression
IPv4 Settings: Method: Automatic (VPN) Addresses Only
I did check out that site you used (freevpnnetwork) and I don't see anywhere to download the certificate so I'm not sure how that works. As far as I know you need a trusted certificate somewhere on your machine when setting up a VPN this way.