Please note that this is Polish Q&A Forum, any threads should be posted in Polish. However, I will still provide an answer on English based on your initial response. If you want me to post in Polish, please let me know.
Welcome Mateusz Kudyba,
I’m really sorry you're facing this situation. I can understand how frustrating and disappointing it must be, especially after taking the extra precaution of enabling two-step verification and keeping a backup recovery code, only to be informed that the account cannot be recovered.
Based on the response you received from Microsoft Online Safety, the account has already undergone a review and was determined to remain permanently suspended. The message also states that, because Two-Step Verification was enabled, Microsoft Support is unable to remove the security protections or make changes to the account's security information.
How to get a Microsoft account recovery code | Microsoft Support
Microsoft account has been locked | Microsoft Support
While I realize this is likely not the outcome you were hoping for, the information provided indicates that the review process has been completed and that the suspension decision is final. Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas.
Thank you for sharing your experience, and I sincerely sympathize with how difficult it is to lose access to an account under these circumstances.