Are you talking about the iOS 6 to 7 transition where the security certificates expired and Apple wouldn't issue a new one and said you needed to switch to iOS 7 if you wanted Facetime to work again? That was my last iOS device.
I don't remember that as I just upgraded the OS. Why would an OS upgrade be some thing you wouldn't do? Seems to me like you have bigger personal issues than some technical one with this situation.
