Push notifications and iMessage won't work on iPod 4th gen refurbished after updating to last ear iOS

My iPod has been working well for a while other than the battery draining very quickly. But just today I updated to iOS 6.1.3 and all of a sudden iMessage won't deliver the messages and my push notifications aren't showing up! I don't know what is making this happen, but this along with the battery issue is driving me crazy!!! Any help would be greatly appreciated!!