Hijacked Apple-ID - possible to recover?

Hello everyone,

i've come to ask about a serious topic. So one of my Apple ID's was hijacked a couple of months ago, the attacker somehow gained access to my account, changed the primary email, passwords, removed my security phone number and added a new one. Although, the attacker did not remove the rescue email, because I've received a mail from apple in which the password gets changed and the changed primary email is displayed there. So the thing is, there were security questions on the account which I remember, I remember old passwords, old data, etc. Even my name and surname are still there, but I cannot start a recovery process because I don't know the phone number the attacker added. Would it be possible for the Apple support to verify my identity that the account actually belongs to me and resets the password? I've had a lot of private data there which is quite important to me.

Kind regards

Alexander