How unlock my phone

All you can do it try to unlock the phone yourself with the unlocking portal.  

https://www.att.com/deviceunlock/

If the phone isn’t eligible for unlocking, it won’t be unlocked, and then all you can do is try to get your money back.  A lot of scammers enjoying selling to people in other countries because it’s difficult to return the phone.

@catcaster  As stated in multiple posts on this forum, a phone won’t be unlocked unless it is paid off, and you cannot pay the amount due.  Only the person who owes the money can.  AT&T will not provide any information on the account, or how much is owed.

The only advice is to get your money back from the seller.  If that isn’t possible, then there is nothing that can be done.

If the phone is Carrier locked, then the seller lied to you and you should return the phone. EBay has a dispute process if the phone is not as advertised.

that was all good but you must understand where am i lіve, and what price have i already paid for shipping and how much will it cost to ship back to america, no one will return it to me

I found out that the phone was fully paid and because of this I wanted to know if it was possible to do with him at this time

I din't abled to unlock my phone, is this even possible as I now have a very cool iPod 14 pro
I tried to unlock through the link that you guys sent me and I saw this

@dwill05 your comment didn't solve my probleme

so I am writing those who work in the company to help me or give me some information to solve my problem

@catcaster 

I think you were missing the point. Your problem is not going to be solved. Whoever owned the phone did not pay it off. Until they pay it off it is not eligible to be unlocked. That's the end of it. There is no solution.

You may have been scammed since you purchased it off eBay. Or the eBay seller may have indicated that it was locked to AT&T and was going to stay locked to at&t. Only you know what the eBay advertisement said.

AT&t's obligation is to the original purchaser, just as that original purchaser was obligated to pay off the phone, and also make sure their account was in good standing. 

You are not going to get a solution from AT&T.  

If you can return the phone then do so and get your money back. Or use eBay help to complain about the seller if the advertisement indicated that it was unlocked or could be unlocked.

You can continue to wait for a response from ATT help which will be a canned and generic response reinforcing that you have already been given the correct answer. You can keep wasting your time with AT&T or go after whoever sold you a phone you can't use.