Proof of purchase to unlock device

If you were working with Apple Support via phone, you need to contact them again. This is a user to user support forum and Apple does not participate here. When you call, use the case number you were provided to let them know what you want.

Activation Lock, presumably.

Bring your device, proof of original purchase, and matching photo ID, to an Apple Store, and find out.

Or ask the Apple folks directly, when you make the appointment.

How did you initially get in contact with Apple Support, and did any if this require you to provide an Apple ID and the associated password? Through a link somewhere here on the Apple web site, or via the list of Apple telephone numbers, or by searching for unlocking in that hive of scum and villainy otherwise known as Google? Because you could well have been in contact with a scammer.

Here is the forgotten-password sequence: If you forgot your Apple ID password - Apple Support

Failing that, there’s: Recover your Apple ID when you can’t reset your password - Apple Support

If you are in the account recovery sequence, it will take as long as it takes.

Here’s the Activation Lock sequence:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Turn off Activation Lock - Apple Support

Here’s the not-yours sequence:

How to request access to a deceased family member's Apple accounts - Apple Support

Inferring from your postings, it seems you’re in the account recovery sequence, and not the bypass-Activation-Lock sequence.

But in conclusion, it’ll take as long as it takes.