Unable to login Microsoft 365 Business

Please note that this forum is a community support space, so I don’t have the ability to access tenant data or perform actions such as resetting MFA/security information directly. I can only guide you based on documented processes and experience, but I will do my best to point you in the right direction so this can be resolved properly.

Dear @Charoensak Narkngam,

I hope you’re having a good day.

I'm sorry to hear that you're experiencing this issue and that your attempts to contact Microsoft Support by phone have not been successful.

First, if there is another Global Administrator in your tenant, I strongly recommend contacting that administrator. They may be able to review your authentication methods and reset your MFA registration, which is often the quickest way to regain access.

Your administrator can follow the guidance in the following article: Manage authentication methods for Microsoft Entra multi-factor authentication

However, if you are the only administrator and no alternative authentication methods are available, this becomes an administrator lockout scenario. In that case, Microsoft Support will typically be required to assist with account recovery and MFA-related access issues.

Since you've already encountered difficulties with phone support, you may consider opening a support ticket from another Microsoft 365 tenant that you can access, if one is available.

If you do not have access to another tenant, you may also consider creating a new trial tenant and submit your support request, please follow this link to create a trial tenant: Compare Office 365 Enterprise Pricing and Plans | Microsoft 365 - after that you will be able to access to Microsoft 365 Admin Center to raise the ticket

Assuming that you have already created an account after registering a free trial and you can go to Microsoft 365 admin center and click Support > Help & support icon to raise your ticket. The agent will be able to create a ticket for you under the affected tenant and then transfer this ticket to Data Protection team who could help you to regain access.

Please mention that you are raising ticket on behalf of the affected tenant that you do not have access to. The support team will help you to create ticket on the affected tenant then later on the Microsoft Data Protection team will assist you.

Note: This process will take more time than usual (7-14 working days) for your account to get access again as Data Protection is always overwhelmed with the number of tickets. As I am forum moderator, I do not have access to Microsoft internal system to assist or push this process to be quicker.

If you do create the trial and it resolves the issue, please remember to cancel the subscription afterward to avoid any related charges. This new trial tenant will not give you access to any of the data or settings in your original locked tenant. It is solely a temporary means to contact Microsoft support.   

I hope my information is helpful. Please give me any updates once you get this resolved

Warm regards, 

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