try to restore the phone if that does not work, get this replaced
[http://www.ebay.com/itm/Samsung-Galaxy-Note-2-II-AT-T-SGH-i317-SIM-Card-Tray-Holder-Slot-Flex-Cable-/231026776195?hash=item35ca44d883]
remember the link i posted is for AT&T galaxy note 2. You haven't mentioned the model number for your phone. so search the eBay with the model number of the phone. these parts are different for different carriers.