How to Unlock my S5?!?!?

So, I read the post, it has some instructions that's not too complicated.
But I'm stuck? Guess where? that's {edited for word filter evasion} american SSN, which I don't have and feel offended everytime people asking when I really need to have a good and nice transaction with them.

First of all, I am(was) International student. so having SSN is nearly, perfectly, impossible. ok?

I bought goPhone, or something spelt like that. Now, I left the US and staying in my home country, Indonesia. And, guess what? I need new SIM card, YES....guess what, it's LOCKED.

So, I heard from Uncle Google that unlocking your phone cost money.
I tried my best to follow simple AT&T self service unlock, that Sh**SosNum(SSN) on my way.

Any help from AT&T costumer service?

FYI, my dad told me that Hongkong or China used to use this system(Phone Monopoly, Locking phone) but then people complain, because indeed no-body like that, and they switched to global.
When iPhone first came to Indonesia, they also used that monopoly system, then guess what? switched right away cause it's {Inappropriate content removed}. there's no offense, only facts.