Just call and ask them.
Here in Canada, I just have to prove that I'm moving to a place where I can't get service (from whatever company I have a contract with) and if I do I don't have to pay anything.
That's the case here too, but when you're the one canceling (not because of service) you'd have to pay. Telling a company "I'm moving out the country can I cancel for free". . . Isn't going to happen, ever.
If you know for a fact you're not coming back here. . . Like Gen said you could just stop paying them.
according to wiki:
"Credit history usually applies to only one country. "