So my fiance has a 4S that has been with Verizon for almost 2 years now. we just canceled it, paid the eary term charge and the bill. Her dad had his ATT iphone 5 stolen recently. So we thought he could use our 4S and put on his ATT contract. They are at the ATT store now and say that the 4S cannot be activated on ATT. I thought the 4S could go either GSM or CDMA? is ATT lying?