@GBC Admin
Thank you for your post!
Since you're trying to log into the Volume Licensing Service Center and are running into issues, I'd recommend reaching out to their specific support team via their Contact Us. Additionally, if you'd like to try and take over your unmanaged tenant as an Admin, you can follow our - Take over an unmanaged directory as administrator in Azure Active Directory documentation.
If you have any other questions, please let me know.
Thank you for your time and patience throughout this issue.
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