How can I recover an Apple Account after the security questions were changed?

Change the password for the email account connected to Apple Account as well, and secure that email with two-factor authentication. Also review your trusted devices, phone numbers, payment methods, and recent account activity if you can access any settings. If the attacker changed the recovery information, official account recovery may be the only remaining option.

If you can still sign in on a trusted, currently logged-in Apple device, check the account settings there and try to enable two-factor authentication or add a trusted phone number. If those changes also require the unknown security answers, you’ll likely need to use Apple’s official account-recovery process. Be prepared to verify ownership with any payment details or trusted devices connected to the account.

This sounds like an older account that still uses security questions instead of modern two-factor authentication. Resetting the password alone may not remove the attacker’s changes or satisfy the additional verification step. Contact official Apple Support or start account recovery through Apple’s account-recovery website, and avoid anyone offering unofficial paid recovery help.