Phone is STILL LOCKED! I m overseas already!

I paid off my phone about a month ago with xifinity, and I went inside the store to check with the agent whether the phone has been unlocked for my trip overseas. The agent confirmed that it is unlocked. 

When I landed, I bought a local SIM card, it said "Enter network unlock code. You phone isn't allowed to use this SIM card". I contacted xifinity assistant, spoke to some human agents a couple of times, contacted Samsung.

One xifinity agent said my phone has been unlocked and referred me to Samsung For issues. So, I contacted Samsung. Samsung said it is against the law to unlock the phone for cellphone owners, and it is the carrier (xifinity here) who locked my phone and not released it.

So, i got back to xifinity agent, an agent named Naman just cut the conversation at the end. So impolite! He ended that it us my local SIM card problem, and asked me to seek for help from local SIM manufacturer, cut the conversation at messenger, and closed case. What kind of customer service is that? So BS!

I am so sure it is not the local SIM card, I spent extra and bought another one to try, NOT WORKING! Tried my mom's SIM as her one worked. IT DID NOT WORK ON MY PHONE AT ALL, SAME MESSAGE ON THAT NETWORK LOCKED.

I just recieved another text message saying case closed. HELLO, THE PHONE IS STILL LOCKED!! The agents and Xifinity are still UNABLE to resolve the problem. I m still stuck with no internet when there is no wifi.

I m just very frustrated about the locked phone and with that Agent Naman's unprofessional behavior. While travelling, for 19 days overseas, it is not pratical to use global pass every single day either.

How can Xifinity still locked my phone when i paid out in full??????

And one more thing by the way, though Xifinity claimed that my phone is unlocked, I have never got any confirmation email or recieve any code to unlock the phone!