You need to check and see if the iCloud toggles are OFF or ON. If they're off, then you need to connect the phone to PC and if the toggles are ON, connect to the iCloud using your browser and you will have the possibility to restore them. If you have previously connected the iPhone to PC, then iTunes created a backup, each time you synced it. Connect the iPhone to PC, then click it and choose Restore from backup. Press that button and follow the procedure.