Activation problem iPhone 5s
I keep trying to activate iPhone did everything from hard reset to plug into iTunes over and over... The iPhone take you through all the activation steps to set up to the welcome to iPhone. I press get started and iPhone then goes inside the iPhone for like one second then black out goes back to Hello screen and then Activation Required pops on screen.. On iTunes it says iPhone can't be activated try again later.. Has anyone ever incountered this problem before?? Someone please help...