LED Flash Alerts

Since my iPhone5 is upgraded to iOS 7.0, the LED Flash Alerts is no longer working. I have asked my friends (7) who have the iPhone5, they are also stunned that it is not working any longer. I went to an Apple store, they are not able to resolve it. I called the Apple Chat online, they are not able to resolve the problem. I was suggested that I back up and restore the system. I have not tried it yet.