I feel like we/you have to be missing something here. I've never heard of international data charges (in this context, traveling/roaming yes but never from US -

I feel like we/you have to be missing something here. I've never heard of international data charges (in this context, traveling/roaming yes but never from US -> Elsewhere). FaceTime is just data, at worst you burned some cell data but it shouldn't matter if you are talking to a server down the street or across the world. You are sure you weren't just being charged for the data at a regular rate? If you can post a screenshot of the bill and if it says something like "International data" or similar that would help.