Recover access to Microsoft-hosted Exchange account with outdated, inaccessible backup telephone number. I am the administrator but with same login problem.

I am in need of an experienced IT professional with Microsoft Exchange and account recovery expertise to help me recover access to my Microsoft-hosted Exchange account. Unfortunately, I do not have access to any email associated with the account, so other methods such as the backup telephone number are inaccessible. I have also tried recovering the account using the authenticator app, but it has since been lost, and my phone has been reset to factory settings with no backup codes. I have already contacted Microsoft Support for assistance, but they were unable to help me. The right individual for this project should have a deep understanding of Microsoft Exchange and account recovery, as well as the necessary skills and knowledge to successfully regain access to the account.