I can't connect to the internet unless i'm on wifi

I upgraded to an iphone 5c from an iphone 3GS. Once i got the phone activated, I was unable to access the internet, unless i was connected to Wifi. I also upgraded my phone plan from the family talk 550 to the new mobile share 1GB. I have NO RESTRICTIONS set on my account, yet everytime I try to access the internet while not on Wifi I receive the message, "We're sorry, but you are attempting this transaction during a restricted time period set by your wireless account owner." Again, I have NO RESTRICTIONS on my account, phone, nothing. Restrictions are turned off. WHY IS THIS HAPPENING???