My iphone won't connect to mobile data?

My iphone 4 will not connect to mobile data or 3G.
It will connect to Wi-Fi perfectly fine, however when i lose Wi-Fi connection i have no other internet access.
on the mobile data section in settings, both "mobile data" and "enable 3G" are turned on.
Any ideas how i can fix this or what has happened?

I would take into the apple store and see what they can do for you.

  • Why won't my xbox 360 connect to the internet but will connect to my iphone hotspot? Ill play cod bo2 almost daily and my xbox will connect to my mobile hotspot on my iphone 4s fine, but out of no where it will lag out and disconnect me from xbox live, its not a hardware issue everything connects normally, full bars and everything the phone still lets me get on the internet, but my xbox will not, why D:?
  • Why won't my iphone 5s connect to celluar data? I have straight talk and my iPhone 5s won't connect to the cellular data. Anybody know what I can do? I've already talked to customer service and they're no help.
  • Why won't my unlocked iPhone 3GS connect to t-mobile? I have an AT&T iPhone 3GS. I jail broke it and unlocked it through ultrasn0w on cydia. But it still won't connect to the network when I put in my SIM card. I also tried SAM, but nothing has worked. Can you help?
  • Why won't cellular data actually connect? My phones cellular data won't connect to LTE. And I have no idea how to make it work, or how to troubleshoot the problem. I have cellular data, LTE, and data roaming all switched on. But no connection. My phone is the iPhone 5C if that helps. Thanks! Ps: I'm permitted to access internet in my plan, but I can't.