Would be interested in knowing how they bypassed 2 factor authentication, assuming you had that enabled.

Unfortunately, it's a tough situation since for all Google or we know you could be the hacker trying to get into the account and hard for them to verify who you are, since if the hacker was able to steal person's phone to bypass 2 factor authentication, they may also have access to a copy of your drivers license or ID to send to google in an attempt to verify they are you.

While far from ideal, assuming you don't have a close friend to contact google for you via their google apps admin account, you could create a new trial google admin account and then contact google through that mentioning your situation of your other account. While they will still have to find a way to verify who you are at least you'll reach a real person.