apple id problems in app store, iphone 5s
i just got an iphone 5s and i'm trying to update my apps. i have entered my correct apple id into icloud and store settings, but when i try to update apps it automatically switches back to an old one. i've been to settings and re-entered the correct id and password in icloud and store multiple times but it always reverts to the wrong one. how can i change this in a different way than before?
iPhone 5s, iOS 7.0.6