@Alan Doyle I fear the agent ended up giving you a completely different Microsoft account.
Launch your web browser in incognito mode. You can click on the three dots in the web browser on the upper right, use the incognito mode, or inPrivate mode.
Then go to https://account.live.com, sign in with your OLD email address.
If it wants you to verify, and if the code is sent to an email address you don't have access to, look for an option like “Show more verification methods” to see if you have a backup (e.g., a phone number or alternate email).
If you don’t have access to any of the options listed, select “I don’t have any of these.” This will begin the recovery process. As part of that process, Microsoft will let you add new contact information — but only after a 30-day waiting period.
This 30-day delay is intentional. It’s a security safeguard designed to protect users in case someone else tries to hijack their account by changing recovery info. The wait gives the rightful owner time to notice and stop unauthorized changes.
Unfortunately, this policy cannot be bypassed. Microsoft explains it further here.
https://support.microsoft.com/account-billing/-your-security-info-change-is-still-pending-or-you-can-t-access-this-site-right-now-microsoft-account-message-cbd0f64f-02d9-45d2-90c3-2375e5a72e52#:~:text=While%20we%20understand%20this%2030,phone%20number%20or%20email%20address.
Once the 30-day wait is over, you will gain access back to your old Microsoft account. And that's the one you want to continue using for your apps too, because your subscription is there.