Can't manage account from overseas

Long shot, but here goes -

I have a Virgin Media account that I pay for and manage for a family member that is now living in my house in the UK.

I myself am based in Canada.

I cannot access my VM account area. When I attempt to login from a Canadian IP, I get an error that the URL is forbidden. When I try to login via VPN, I do at least see the login page, but entering my email dumps me right back to the start. I can't get beyond the email entry screen.

Who do I contact to lodge a tech ticket to allow overseas access?

I realise this is probably an edge case, but it's very frustrating not being able to manage my account to update payment details or do basic things, without relaying those instructions to a family member to do it on my behalf. The account is in my name and I'd prefer to keep access private.

Thanks.