Hello @Keith Morgan
Thank you for posting question to Microsoft Q&A Forum.
As far as I know, the Business support is included in Microsoft 365 package.
Please check on this link: https://support.microsoft.com/en-us/office/microsoft-365-customer-service-and-support-96162163-b3aa-498b-bbbb-5e757b0f31da

It might be difficult to find the callback support if you have technical issue with Outlook 2021 (which belongs to Office 2021). My apology for any conveniences caused by this issue - as this forum is peer-to-peer support so I could not check the ticket system to provide you an answer about your ticket question.
Regarding Outlook 2021 issue, may I know if you have had this issue when opening Outlook 2021 like this screenshot?

Did you recall on the part MS Support Team tried to reset Outlook profile ? Was it related to second part in Q&A Assist's answer?

If it does not work, please search for the app "Get Help" in your computer, then type "Cannot open Microsoft Outlook" and select the PC > Office 2021 > proceed with troubleshooting steps there.

I hope this could possibly help while you are waiting for answers about the ticket at the moment. If you have more questions/update about Outlook, please feel free to ask here.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
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