Is Your Phone Refusing to Allow You to Change Any Setting After Your 9.x Upgrade?
Your out of luck I'm afraid.
My daughter was cursing me for updating her iPhone to iOS 9. She told me it had screwed her settings up. I didn't believe her at first, boy was I wrong!
She is an extreme user of her phone and turns everything off until she needs them. In this case she only had a small number of Apps set to use mobile data. After the upgrade those that where previously turned on couldn't be turned off and those that where off couldn't be turned on.
I was stumped.
I reset the Network Settings, didn't fix it. Then I reset All Settings, still no joy. Then I Googled it.
What I found is that a years old iOS bug (and how many of these are there Apple?!?) was the culprit. When the Settings.db file on the iPhone becomes damaged, the Settings App can no longer change any setting (it's like the file is now read-only). Worse still, is that a Reset All Settings does not repair the file. The only solution is to Erase All Content and Settings and set the phone up as new (you can't use an old back up because it won't reinstall the damaged Settings.db file).
The moral of the story: always back up before you do an upgrade and then immediately after restore three phone incase damage of this kind happens and you don't find out till its too late.