I am also unable to create an account. My broadband has now been installed, but whenever I try an create an account I get the following error (also included screenshot):
Sorry!
We are not able to set up your my Virgin Media account at the moment. Please try again later, or you can also set up your my Virgin Media account at the time of your broadband installation. We are looking forward to connecting you to your superfast broadband.

I have attempted using different email addresses, but it fails each time.