doesn't allow to turn on battery percentage
I have an iphone 4S I had it for about a year... a year and a half maybe and it has this problem... It doesn't allow me to turn on battery percentage. One day it randomly turned off my battery percentage and when I tried to turn it back on it doesn't allow it. I tried turning it on so many times, but it just turns it back off. I tried turning the hole phone on and off, but it still doesn't allow me to turn on the percentage. Is there something that I can do or do I have to take it to the apple store?
iPhone 4S, iOS 8.2