how to remove Office 365 from mac OS Monterey 12.0.1

Do you still have the MS Office apps in your Applications folder? If you do you might try AppCleaner. I use it and it's very safe. You make the decision of which supporting files to include in the deletion. I would run it on each of the MS Office apps, Word, Excel, PowerPoint, Outlook, etc. Probably the first one you get will find most of the supporting documents for the rest of them but run each individually.

WARNING: If you use AppCleaner on an app that you have other apps from the same developer, like Adobe, you must be extremely careful checking all checkboxes and deleting.  Some for those files may support other apps from the same developer and deleting them can mess them up.  Adobe apps is a primary example. I know from experience.  For singular apps from a developer it's safe.

Uninstall Office for Mac

Have you contacted Microsoft for assistance with their product?

What did they say?

Thank you for the update. Looks like Old Toad

gave you the solution.