Can't update or restore

Hey I have a iPod touch 5 with iOS 7 GM but I want to have the GA version and am trying to put it back on iOS 6.1.3 and then update but I can't...when I connect my ipod IOS 7 GM to itunes 11.1 it always says """connect this iPod touch using a USB cable in order to update or restore it's software""" that's what it says and I already disconnected and connected my ipod but it says the same thing and the usb cable is the original... I don't know what to do please help me..