Apple ID hacked. phone number changed, cannot recover account

My Apple ID has been hacked. The hacker changed the password, phone number, and billing information. I still have access to the Gmail address linked to the account and can see notification emails of their activity.

The problem is that when I try to recover the account, Apple asks me to type in the phone number associated with the account, but I don’t know it because the hacker replaced it with their own number, and now I have no way to find out what number they put.

Based on the notification emails I’ve received, the hacker appears to be operating from Brazil.

I cannot recover the account through any of the standard options since they all require entering that phone number. I also cannot reach Apple Support via email through the normal channels.

Has anyone successfully recovered their account in a situation like this? where the phone number was changed by an unauthorized person and you don’t know what it was replaced with? What is the best way to verify identity with Apple without needing that number?