Unlocking phone

I bought a phone from a girl. After I reset the settings I can't activate it.
I tried to use the services and see the message:

You can’t unlock your device until your installment plan is paid off. If you pay off your device as part of your monthly bill, wait until the start of your next bill period to unlock it.
Want to pay off your device early? Make sure your number has been active on the device for at least 60 days. The, sign into your account to review and pay off your installment plan. Wait 48 hours after you make your final payment to submit a new unlock request.

I can't even log into my personal account because I don't know the billing zip code data. How can I unlock my phone?

You likely got scammed.  If you can't get your money back, it's likely you have a brick.

   AT&T phones are not only carrier locked but they are account restricted. That means a phone that's not paid off can't even be used on a different AT&T account

You cannot pay off someone else's phone

If you have your own AT&T account, why would you not be able to log into it? Why would you not know your billing ZIP code?

Hello@alexey1cdeveloper, we're here to help you.

We would like to let you know that please ask original account holder of the cellphone to contact us to unlock the device.

Thank you.

Susan, AT&T Community Specialist

@ATTHelp Could you tell me? I can use any e-sim in the phone and there is no SIM lock in the device information, but at the first activation, the iPhone already had an AT&T e-sim and it will connect to the AT&T network to activate it. Now this e-sim has stopped working. It turns out I won't be able to activate the iPhone anymore and it's still locked? Could you explain?

Hello @alexey1cdeveloper,

We want to inform you that it seems like you have an iPhone with an eSIM that was originally activated with AT&T, and now you're encountering issues with that eSIM. If your AT&T eSIM has stopped working, it's possible that AT&T deactivated it for some reason. This could be due to non-payment, a change in your AT&T plan, or other account-related issues. Please ask original account holder of the cellphone to contact us.

Thank you.

Susan, AT&T Community Specialist

@ATTHelp  Hello! Could you tell me, please. Is my iPhone a contract? if I can use the e-sim of any operators. I want to find out what restrictions I have on my phone, how can I do this? When I bought it, it was sealed and inactive. The first time it was activated, it connected to the AT&T network

@alexey1cdeveloper 

Susan from ATT help has given you the correct answer twice. AT&T cannot help you. If you cannot track down the original owner of the phone and get them to pay it off so that you can unlock it, you have a brick, a very expensive very large iPod touch.

@formerlyknownas I just want to understand the status of my device, if it was a contract, could I use the sim of other operators?

Hello @alexey1cdeveloper,

We suggest that if your original account holder for the iphone please contact our customer care at 800-331-0500 with account information as they will be able to assist you.

Thank you.

Susan, AT&T Community Specialist