Cannot connect to I-tunes

I purchased ipad 4 (retina display) in January.. While it has worked well till now, I now find that none of my apps are getting updated since my ipad cannot connect to I-tunes store.. So all the updates are pending.. What's worse that I cannot update to iOS 7 since it just doesn't connect to I-tunes store.. My wifi connection is good enough and I can easily browse the Internet through my ipad.. But the problem persists only with I-tunes.. I have already tried following steps mentioned in the apple support site about the date and time settings and checking my wifi connections.. Still no luck.. Ne suggestions? Thanks..