Old non-Virgin email address used as my primary account has been shut down

My primary account email address was changed 11 years ago to an email address I never used. (I was moving home and VM assured me it only needed to be unique). Therefore I gave the one I was using briefly at a school I was working in.  Prior to that my primary account was an ntlworld address which is still the only VM email I use but, as I understand it, is my secondary account.

However that new primary account address remained as my primary account mailbox despite me having no access nor need for it for 11 years and is now defunct.   Having not been an issue for the past 11 years it has become one now.

I understand I can alter the primary to, for example, my google mail address. However currently the first step after entering the old school email is "We have sent a link to...<<old defunct email>> for verification". I cannot access this as it does not exist.

I try to start Sky sports app on my andoid tablet. I try to login like I used to a month ago using the old school email and ........ "We have sent a link to...<<old defunct email>> for verification".

I have raised a ticket 9 days ago (no reply yet!) but I feel the first step is to make my primary email one that I can access.

Does anyone know how I can do this? Is anyone at VM able to help?