Account restore with 2fa

Microsoft has made recovering a Microsoft account with 2FA protection enabled only possible for those with access to the verification methods selected for that account, since they'd clearly had problems with situations where their support agents had been tricked (or claimed to have been by customers) into giving account access to others to whom the account didn't truly belong.

See the note at the end of the following list of FAQ entries, which is also displayed on several other Microsoft official pages relating to personal account access issues similar to yours, like the one that follows. The bold text is mine to accent the pertinent portion.

"Note: If you're still not receiving verification codes, you may have to choose another method, or wait until you can access the phone or email you've listed. To protect your account and its contents, our support agents are not allowed to send verification codes or access and change account details."

Troubleshooting verification code issues - Microsoft Support

Contacting support for a Microsoft Account - Microsoft Support

Clearly Microsoft has decided that placing the responsibility for keeping the maintenance of 2FA account verification and other details before too many are lost on the customer where it's always belonged, with the potential result that neither the customer nor anyone else including Microsoft itself are able to access the account contents, is the only viable method to ensure the security of the personal data.

Rob

no one from the more serious specialists has come up with another solution, the only way to recover the data is to contact the DPC, I don't see any other way out then

DPC only works if the account is a work or school and you are the only one with the access to make changes to the Azure tenant. It's not possible to use the DPC for Microsoft Personal accounts, since from my understanding they can only manage Azure Work or School accounts and have no access to the Personal accounts because that system is entirely separate and unrelated.

but old xbox game purchases from a bank statement or id card wouldn't help either

It is not possible to fake the purchase dates of old games to match those in the account.

If it's a personal Microsoft account (Outlook/Hotmail/Xbox), go to "I forgot my password" → "I don't have any of these" and fill out the recovery form from a previously used device/network: enter as much real information as you can remember (old passwords, name/address, last 4 digits of gift cards or codes, Xbox gamertag/subscriptions, email contacts/subjects, OneDrive/Outlook folder names, devices used, year created). You don't need perfect dates; don't make up data: several partial but correct answers help more than a single precise one. Submit and wait for the result; if rejected, wait the indicated cooldown and try again with better details (receipts, statements). If it's a work/school account (Sign in ID), only the tenant administrator can unlock you: request an MFA reset or a Temporary Access Pass (TAP) to log in and re-register your Authenticator/phone.

I have two numbers on my account: one that I no longer have, and one that I do have. If I enter it instead of my email address when logging in, it says I don't have one of these methods, and it shows another old number that I don't have. I don't understand why support can't find that number instead of the email address I log in with and send a recovery code to it. This should be possible if there is at least one number assigned to the account.

I have two numbers on my account: one that I no longer have, and one that I do have. If I enter it instead of my email address when logging in, it says I don't have one of these methods, and it shows another old number that I don't have. I don't understand why support can't find that number instead of the email address I log in with and send a recovery code to it. This should be possible if there is at least one number assigned to the account.

You don't have to (and can't) "invent" dates: for recovery, real signals matter, not absolute precision. In short: if it's a personal Microsoft account (Outlook/Hotmail/Xbox), go to "I forgot my password" → "I don't have any of these" and fill out the recovery form from a device/network previously used with that account, providing as much real information as you can remember (old passwords, last 4 digits of cards or gift codes, Xbox gamertag/subscriptions, items purchased, including the approximate month/year, email contacts/subjects, folder names, devices used, year of creation). Submit once and wait for the result; if rejected, wait for the cooldown and try again with better details (receipts, statements). If you have a 2FA recovery code, use it; the Authenticator backup doesn't bypass login. Immediately after logging in, add at least two MFA methods (Authenticator on the new phone + SMS/FIDO2). If it is a work/school account (Enter ID), only the tenant administrator can intervene: request a reset of the MFA methods or a Temporary Access Pass (TAP) to log in and reconfigure the Authenticator.