Thank you for posting this in Microsoft Q&A platform.
If none of the global admins are able to login and are blocked entirely, you can reach out to the Azure Data Protection team to restore access. 866-807-5850
Also, for the future, you can create an emergency access account (break glass) in Azure AD and exclude this account from all the conditional access policies. This account will help prevent being accidentally locked out of your Azure Active Directory (Azure AD) organization because you can't sign in for any reason.
https://docs.microsoft.com/en-us/azure/active-directory/roles/security-emergency-access
Some other support option include;
azcommunity@microsoft.com
or creating a ticket through a different account: https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide#phone-support
Let me know if you have any further questions.
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.