Deleting an old ntlworld account

I need to have an old ntlworld e-mail account deactivated. I have not been a Virgin customer for several years but it appears the account was never properly deactivated and i have just received e-mails forwarded to me stating that someone has reset my password for accounts registered with companies. I am concerned that someone is using my identity. Can someone at Virgin please contact me to advise how to do this. Thank you