I reset to factory mode and this did not resolve the issue; only some of the apps reappeared under cellular settings. This was a week ago, and I haven't backed up my phone since b/c I was hoping I could find a solution, and back up without a full loss of data.
In the meantime, I'm back to paper & pencil calendaring, record keeping, etc. until I decide to stick w/ a phone that cannot take further updates, cannot keep up with professional and personal tasks, and might function if I delete and restore all apps, or shelling out an outrageous amount of money for a newer phone, knowing that I'll face the same situation in as early as 2 years if I choose the iPhone 6.
I'm posting all of this for 2 reasons: one, so that others know that restoring does not resolve the issue, and two, to vent frustration about paying so much for something that will become obsolete so quickly.
Three weeks ago, text messages and contact names disappeared from the phone. I googled the problem and realized there was an update (the phone didn't notify me as it had with previous updates). The phone wouldn't take the update. I deleted apps to increase storage to make room for the update, and after several other troubleshooting attempts (for example, updating from iTunes instead of wireless), I took the phone to the Genius Bar. They were able to push the update through but not resolve the issue of the apps not showing under the cellular settings.
A follow-up call from Apple advised resetting the network. No success. Next was a resetting of the phone, which lost more settings than I was told/realized. Then came a transfer to a supervisor, who advised restoring the OS on the computer. This didn't work, and now the phone wouldn't back up. 3 hours later, I was advised to contact Sprint.
After an hour with Sprint, I was advised to take the phone in to a service center to have them back up and restore the phone.
Before going to Sprint, I went back to the Genius Bar who checked the OS and the update, retried both resets, and suggested restoring the phone to factory mode. They also suggested the problem might be with an app.
Sprint checked the phone and said it wasn't a Sprint issue.
Apple also said that the iPhone 5 will not be supported with further updates...