You can't surf the internet if the data is not in a position to change into ON, here's how:
- Go into the settings menu
- Select Mobile + SIM
- Switch Connection data into a position ON
- On below, there is SIM option SETTINGS in which there is a choice of reference data connection (2G and 3G) and the name of the corresponding network SIM card what you wear (auto detection).
For more details of how the data connection settings, see below could use some pieces of the picture.