Hello @Will Ford,
Welcome to the Microsoft Q&A Forum, and thank you for taking the time to explain your situation.
Based on the information you’ve shared, I understand that you recently purchased a Microsoft 365 Business Premium license but are currently unable to access it. I know this can be frustrating, and I’m here to help guide you through the next steps.
First, if the issue is related to using the Business Premium features, please make sure that the license has been successfully assigned to your user account. Without assigning the license, the services included in Microsoft 365 Business Premium will not be available. You can review or assign licenses by following this guide: Assign or unassign licenses for users in the Microsoft 365 admin center - Microsoft 365 admin | Mic…
On the other hand, if you are unable to access your account itself (your password no longer works, MFA is not launching, or you are locked out) and you are the only admin of your tenant, then the issue requires a different approach. In this situation, Microsoft’s Data Protection Team can help you regain access. They use secure, verified procedures to confirm your identity and restore administrator access when no other admin is available to assist.
Please note that forum moderators have no control over user accounts, especially when it comes to logging in to your account, resetting your password, changing your access, etc.
Therefore, please try to find the related hotline number to call the frontline let them raise a ticket for you: Customer service phone numbers - Microsoft Support
Here are some tips and an example of a prompt to help you navigate the IVR more effectively:
(When you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)
In some regions, the initial interaction may be automated, so here’s a general idea of how the conversation might go to help you prepare:
What kind of problem are you experiencing?
Answer: Authenticator
What products do you use?
Answer: Office 365 for business
Is this for an education or company account?
Answer: For companies
Are you an administrator?
Answer: Yes
Are there any other administrators in your organization?
Answer: No. I am the only admin in my tenant
Do you need a... Service request?
Answer: Yes. I need to create a ticket. Please send me direct to the Data Protection Teams.
If your organization's Office 365 Business/Education subscription is from a partner or reseller, and the global administrator is unable to open a service request on your end, contact the reseller's support provider to help open a service request on behalf of you instead.
I hope this information helps you take the right steps to regain access to your account. If you have any updates or additional details, please feel free to leave a comment under this post. I’ll be happy to assist further within my scope.