Hello,
You are correct, if the tech team determines that the information given indicates that the petitioning player is likely not the account owner, they will not give additional information out.

Fortunately, you can still rectify this issue by using the account recovery tool or creating a CS ticket to give them the information they need. Please be aware that the ticket route will require more stringent information. It sounds like you have already used the account recovery tool, so my suggestion at this point would be to use it again and resubmit (properly) your information, or to create a ticket referencing your situation and your previous information and to provide the new and updated information that is requested.
Here are the links to the two platforms.

Unfortunately, those details will have to be discussed with them. If you cannot give the information requested in the recovery tool, they will ask you for specific information in your CS ticket. Provide them the info they ask for there.