Thank you for your post! I have heard of such a reward. Did you receive something in the mail? Do you have a reward id? I'm sorry but I'm not sure which website you are referring to. Have you checked AT&T Reward Center?
I got one in the mail yesterday. It is a coupon for a free movie and a $15 reward card. You have to enter the information on the rewards page. This on says att.com/pizzatime and it takes you to the regular rewards page. You enter your account number and it says the reward card will be mailed in about 30 days. It says you can use the reward card to buy a pizza or whatever you want.