Did you receive a welcome text message when you arrived abroad? Can you send & receive texts subsequently? Can you make & receive calls?
Trying to establish whether you are roaming (connected to a foreign network) and this problem is data-specific.. or if the data is coming from WiFi and your underlying issue is lack of roaming. Different problem means different fixes.
The billing account has nothing to do with the permissions needed to use services abroad, those are all on a per-phone basis.
