Why can't I use cellular data?
My data randomly shut off. I have great signal but, no 3G 4G or LTE appears on the screen. I can only use wifi.
iPhone 5c, iOS 7.1
Contact your carrier. They are the ones that control whether or not your device will receive data or not on your account. If the account is showing signal but not data indicator after the carrier name, they need to check the provisioning of your account. You may need to have the SIM replaced. Before you call them, you might want to try a reset, this will not affect any of your content. Hold the sleep/wake and home buttons together until you see the Apple logo and then release. The phone will reboot.