I recently moved away from home for school and where I moved to I'm roaming constantly. My phone started not receiving or sending texts to people without iMessage. I turned my iMessage off to try to send myself a text and make the others come through and now my iMessage won't activate. I can only receive phone calls now. I've tried everything to fix it. Turned my phone off and on, reset all my settings. Nothing works.
That would be the issue. Contact your cell phone provider and see what they can do the help you with your cellular data issue.