Hello, Brasil42!
Thanks for posting. If you have access to a computer, you should be able to click on the link below to refill your GoPhone account.
If you don't have access to the internet and calling in is not an option, you may want to wait until you're back in the US to refill your phone. It's a fairly quick process, and it would be effective right away.
Let me know if you need any other help!
-Mariana