Hi there, this is Marc. Thanks for reaching out to the community.
If the system only shows your old phone number and you cannot receive codes, the first recovery option is to use the Microsoft account recovery form: https://account.live.com/acsr. Please provide as much detail as possible, such as old passwords, billing information tied to the account, or subject lines from emails you sent. Guidance on completing the form is here: https://support.microsoft.com/en-us/account-billing/help-with-the-microsoft-account-recovery-form-b19c02d1-a782-dee6-93c3-dc8113b20c42.
If the account was blocked due to unusual activity or closed by Microsoft, you can also request a review through the Account Reinstatement form: https://www.microsoft.com/concern/AccountReinstatement. More details on locked accounts can be found here: https://support.microsoft.com/account-billing/account-has-been-locked-805e8b0d-4141-29b2-7b65-df6ff6c9ce27. Please note that both processes are handled by automated systems, and Microsoft support cannot manually bypass or change the phone number linked to the account.
If recovery or reinstatement is unsuccessful, the only option is to continue with your new Outlook account and update your login details for services like Xbox, Minecraft, and Epic Games to the new address. I know this is not the outcome you were hoping for, but account access is fully controlled by security systems and cannot be overridden by support staff.
Best regards,