Hi,
Sorry, that is a frustrating place to be stuck.
The thing that will unblock you fastest is separating the two problems. The account merge is one issue, but the panel discussion does not actually depend on it. Every Accredible credential has its own public verification link, and those work regardless of which account they sit under. Pull the links for each certificate from the original issuance emails and send them directly to whoever is coordinating the panel. That gets the scheduling moving while the account issue is still open.
On the merge itself, worth checking whether you can add the second email address to your Accredible profile rather than waiting on a deletion. If the credentials were issued to that address, linking it can surface them in one place without anyone having to merge anything.
For the ticket, reopen the original rather than filing a new one, and reference the previous ticket number so the history stays attached. New tickets tend to restart from zero. It is also worth posting in the Certifications board here, since Databricks staff monitor that one and have escalated credential issues before.
Good luck, and I hope the panel gets scheduled soon.