Network Provider Locked - SIM locked

To get a phone unlocked, you must use the unlock website. The phone will be unlocked if the requirements to unlock are met. 

https://att.com/deviceunlock

If you have issues submitting a request which is common for users abroad, try using a vpn to a US based network.

Thank you for the advice but my request was declined. They say I must pay my account, but I don't even have an account with them.

That likely means you bought a phone previously owned and not paid off. There is likely nothing you can do to get the phone unlocked. You should not have bought a phone locked to ATT if you didn’t intend to use it on ATT. Return the phone and get your money back, if possible. 

I bought the phone on Amazon and it is fully paid off. I did not know it was ATT specific, I thought it was unlocked. honest mistake. 

@xandrilubbe

We understand that. But it's last year's phone and whoever owned it resold it and has not paid it off which means AT&T will not remove the carrier lock. You can't use it, return it to Amazon