All is not lost if you want to go back to jellybean. As long as you are still under Samsung warranty you can go to a at&t with a service center and exchange it . Just make up any good reason and they will give you a new one. It is refurbished but it is a downgrade option.
Sent from my SAMSUNG-SM-N900A using xda app-developers app
Sent from my SAMSUNG-SM-N900A using xda app-developers app