Thank you for the prompt response and also for putting this up as a new thread, Graham.
Some additional details:
Thilocked account refers to my original ntl e-mail and it was first compromised some years ago. It shows up on haveibeenpwned. The password was reset some time last year following an earlier letter from Virgin that it had been used for spamming. There is now a new letter, received today, indicating "suspicious activity" and as a result, the account has again been locked. I seldom if ever use the account now but I do need to access it to secure it with a much stronger password. This is not possible for me online due to Virgin's security procedures.
When I went to virginmedia.com/myvirginmedia there was no button "forgot password" that the letter said to use, so I attempted to log in. This required a username (my ntl e-mail address) and password. The letter told me to click the "forgotten password" link which I did. To verify my identity, the system required DoB and mother's maiden name. Despite my age, I still remember these and after several attempts with and without a capital letter in the surname name, it is evident that these must have been changed too to prevent my re-accessing the account. A hack is pretty clear, I think, especially as the password was not especially strong.
Next I went down the path of indicating that I'd forgotten the answer to the security question. I had to enter the account number and area reference (which I could as they are on the letter that I'd just received), but I could give neither the date of my last bill nor the amount paid because there is no paper record of them and my ntl e-mail where they actually go is the one I cannot log into in the first place. It would be better if Virgin sent them to my gmail account (I know this can be done; I just haven't looked into it). I no longer use or have a dedicated e-mail client that I can use to access the e-mails after the demise of Outlook Express so all my access to this account would be via the Virgin Media web site interface.
So that's it. What I'd like help with please is getting into my ntl.com e-mails so I can get the info I need and unlock the account. I'd prefer not to try to phone for help given the current health situation and the time it took to do this last year when this coronavirus hadn't been created.
Any help most gratefully considered. I'll get the password thing under proper control!
I think that I effectively killed my own thread by marking the first reply (which moved it from the wrong place to stand on its own) as "helpful", not realising that the thread would be flagged as answered.
Is there any assistance available to resolve my problem or should I ignore the inability to sign into my Virgin Media account? It's not that I use it but it would be useful to be able to access my bills if I needed to.
I can't do anything that is in the letter. The process fails because my password is not as I left it when I last accessed the account.
If I attempt to go around this by indicating that I've forgotten my password, I have to establish my identity by answering the security questions. My responses have not been accepted by the system. When I indicate that I cannot answer these questions, I have to give my account number and area code - which I have done but the system then wants the amount and date of my last bill. This information is locked inside the account that to which I'm trying to gain access so I'm completely stuck.