Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Unfortunately, it will not help since the security info has been changed.
Please be advised that Microsoft Support will not be able to assist you with manual recovery, unblock, and escalation for this case, as stated in this article, that they are not permitted to send password resets, access, or even change any details on the account: https://support.microsoft.com/account-billing/help-with-the-microsoft-account-recovery-form-b19c02d1-a782-dee6-93c3-dc8113b20c42
Moving forward, please check this link for more information on how to secure your account and to prevent hacking incidents: https://support.microsoft.com/account-billing/how-to-help-keep-your-microsoft-account-secure-628538c2-7006-33bb-5ef4-c917657362b9
Please note that this is a public forum, I will be responding you in short period of time and regret for a delay in response.
Best regards,
Darhyl