Unable to register for an Virgin Media online account

Hello - I've been trying to register for an online account with Virgin Media for the past 3 weeks. I'm 100% sure that I've entered all my details correctly (surname, account number (from an email sent from VM!), area code). Each time I get a "We can't find an account with the details you've provided. Please Contact Us to register." message.

I've called customer service 4 times by now - each time the support person also says they are unable to create an account on their end and that they will escalate it to their technical team. No one ever comes back to me with a resolution and I'm stuck in this ridiculous cycle.

Please advise on what I can do - or how I can solve this as it's REALLY getting on my nerves.

Thanks for all the help!