Phone Won't Accept Correct Sim Card

I purchased an iPhone 5 from someone through classifieds and they had said it was with Rogers. I tried using my Rogers nano sim and won't accept it for activation. I have tried activating it through iTunes as well with no success. I called Rogers support and gave them the cell phones IMEI # and they confirmed that it was with Rogers. I am not sure what else to try. Any help would be vastly appreciated.