IPhone 5c battery draining while not in use

I have an iphone 5c and the battery drains while I'm not on it.
I fully charged it, and after I took it off the charger, I did not get on it. I checked my phone a few mintues later, and the battery drained quickly.
Can anyone explain why this is happening? I have turned of things like location settings, but nothing is working.

Turn the phone off, wait a few seconds and turn it back on. Sometimes a reboot will correct the problem. If that doesn't work, you may have to take it to an Apple store to be checked out. Be sure to backup all of your apps, data and music before taking it to the store… Just in case they have to exchange it for you.