Acrobat XI Pro perpetual license: "too many activations", original Adobe account no longer accessible – need activation reset

Hello, we own a perpetual license of Acrobat XI Pro (serial number license, not a subscription).

We run it in a Windows VM (Parallels) and are still happy with it.

After reinstalling, activation fails with the message that the serial number has been activated too many times and that we should sign in to the associated account to deactivate old devices.

The problem: the license was registered years ago under our former company with an e-mail address on a domain that has since been given up. The domain no longer exists, so we cannot sign in to that Adobe account or reset its password.

Registering the serial number in our current Adobe account fails as well (already registered). The support chat bot refuses to connect us to an agent because this account has no active subscription.

Could an Adobe staff member please reset the activations for this serial number, or tell us how to reach a human agent for a perpetual-license activation issue?

We can provide the serial number and proof of purchase via private message.

Thank you.