If you are syncing your contacts from your PC with iCloud, they are not transferred to your phone using iTunes. They are synced to your phone using iCloud, either over wifi or your cellular data network.
First go to icloud.com with your computer browser, sign into your account and open Contacts there to confirm that your contacts appear. If they do, go to Settings>iCloud on your phone, sign into your account and turn Contact on. Assuming your phone is either connected to wifi or your cellular data network, the contacts should then download from iCloud to your phone.