Who I have the same questioned this topic

Maybe a software restoration will do the trick. Try to download iTunes first on your computer, then open it. Turn off your phone, then press and hold its home button, after 10 seconds continue holding it, but this time, you will plug its cable from the computer (with the itunes) to your iphone 5, then an iTunes logo will appear on your phone, that means you need to check your computer and select the "restore" option, that does the trick for most bugs you encounter. But before doing this make sure to backup your content okay?