NTLWORLD account deletion

Hi, my wife has an old NTLWORLD.COM email address which has been hacked and is now being used by the hacker for nefarious purposes. How do we lock and close down the account. She is no longer a VM customer and cannot log into the account but was receiving emails.  I also have an old NTLWORLD account which I cannot log into and think it would be best to delete that too, I am a VM customer but using a different username and email address.

Regards

I