I can't use my phone's internet connection

Data roaming is turned off

Turn on data roaming.

1 of 7 steps Slide your finger downwards starting from the top of the screen.
2 of 7 steps Press the settings icon.
3 of 7 steps Press Mobile networks.
4 of 7 steps Press the indicator next to "Data roaming" to turn the function on or off.
5 of 7 steps Press OK.
6 of 7 steps Press the Home key to return to the home screen.