Hi Taskkent,
Ideally you should have another account as a backup in case the primary account have issues, it is known as breakfix account. However in this instance if you are the only admin of the tenant the only way to recover is to call up global numbers and provide the ownership and identity proof of the tenant that you own it.
Just keep identification and ownership details of the Business Account handy when you log the call with MS.
Hope this helps.
JS
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