Q: iphone 6s stuck on slide to upgrade

just got my iPhone 6s yesterday and midway through setting up, the message; slide to upgrade popped up with a blank screen. i was unable to do anything aside from putting it on sleep/wake up. any ideas on what to do? i tried turning the phone on and off and the same thing happened again. I also tried plugging it into itunes on the macbook and i got a bit further into the set up but then the message appeared again. now its saying it can't update and i can't do anything on the phone. please help