Snapchat Push Notifications

My snapchat opens and instantly a message appears that says "CONNECT TO ITUNES TO USE PUSH NOTIFICATIONS". i push ok and the message disappears and instantly reappears and continues to do so over and and over again. i have plugged my phone into my pc and SYNC'd it several times with itunes. i have also deleted and re downloaded the app several times. i still have not been able to resolve this problem, can anyone help me?