Firstly, sorry you are having problems, hopefully we will be able to get you connected without much further ado.
Error 720 is a Windows error that can occur when using the PPTP or L2TP protocol. It usually indicates that something has become corrupt in your settings.
Please delete the existing VPN connection and create a new one. Hopefully this will resolve the issue.
If you continue to have problems, please try our alternative VPN technology that uses the SSL protocol. This usually performs better in circumstances where users are having difficulty using our standard VPN.
Full instructions for setting up your connection via SSL can be found on the following links:
Please give that a try and if you have any further problems, get in touch by sending us an email to firstname.lastname@example.org and we will do our best to assist you.