I solved the problem of my Chilean friend by using Tunnelbear, it gives you 500MB for free that is enough to just login on the game.
So basically you'll:
1- google tunnelbear and download and install it
2- Open it and choose United States
3- When on the top of the program appears written "connected to United States" you'll open your xiv and login but don't press the play button yet
4- Click on the ON button to turn it OFF and now you finally click play
5- Profit

Unfortunatelly i have no fix for the ppl on PS4 =(