When updating to iOS 7, my iPhone says Could Not Activate iPhone?
I have an iPhone 4s that is not activated; I used to have Sprint, but my service was shut off. I can still use it when I have access to Wi-Fi. I just updated to iOS 7 and was going through setting my phone up. When i got to the step saying "It may take a few minutes to update your iPhone". After waiting, my phone said "Your iPhone could not be activated because the activation server can't be reached. Try connecting your iPhone to iTunes to activate it, or try again in a couple of minutes. If this problem persists, contact Apple Support at apple.com/support". I connected my phone to iTunes to retry activation and searched on Apple Support, but could not find out what was wrong or something I could do. Does this mean I can't use my iPhone with iOS 7 if I do not have an activated iPhone? If so, is there anyway to change back to iOS 6 or get out of the set up screen?