@bdukes- I'm a little fuzzy on this. Why does an upgrade need to be transferred if it's expired? Can't upgrades be purchased by another Admin on the same site?
I believe the reminder emails were sent to an admin who no longer works for our company.
@wglhendry- If that Admin registered the site on WordPress.com and then left without transferring ownership of the site to someone else in your company, you have a larger problem than just an upgrade renewal. Sites on WordPress.com are owned by whoever registered the site. That is WP.com's current policy. Perhaps @bdukes could contact you privately to provide the additional proofs showing ownership of the site.
To that end, I've tagged this thread again for staff assistance. Please be patient while waiting since there is quite a backlog of threads for their attention.
Also, hopefully your company owns/has access to the domain name itself. If you don't have access to that, no upgrade here will help.