Dear Mike,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
Based on your description, I understand that you need a receipt for the recent renewal fee of your Microsoft 365 Apps for business subscription and need the accounts combination.
Gegerally, you can access your billing information and receipts by signing in to the Microsoft 365 admin center. Once you are signed in, go to the Billing > Bills & payments section to view and download your receipts.
Regarding your request to simplify your accounts into one, I suggest contacting Microsoft support directly for assistance with this matter. They will be able to guide you through the process and help you consolidate your accounts.
For this standard process, here's the official document for the global admin: Get support - Microsoft 365 admin | Microsoft Learn (online option)

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Note: End user need to contact Office 365 global admin to perform some standard procedure.
Regarding the two-step verification process, I understand that it can be frustrating at times, but it is an important security measure to protect your account. If you need to update your phone number, you can do so by signing in to your account and going to the Security & privacy section.
I hope this information helps. Let me know if you have any further questions or concerns.
Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Thanks for your precious time. Have a nice day.
Sincerely,
Sherry | Microsoft Community Moderator