Can't link VM and O2 as my VM Account is registered to an old email which no longer works

My VM account was set up a number of years ago it was registered with an old email address which no longer works and I have no access to. I have updated my account with a different email, which VM use to contact me.  I have set up a Virgin Media O2 ID and have tried to link my Virgin Media account.  When I try to link the accounts it finds my VM account but states that the email addresses do not match and my VM account is registered to the old email.  It wants to send a verification link to the old email, which I will not receive.  I have explained this through online chat and customer service.  I requested that the old email address is removed and replaced with my current one, however, the issue has not been resolved. Can anyone advise, as I don't want to waste anymore time on this? Thank you.