AT&T reward card expired?

 I'm using AT&T internet and wireless, and I, in December 6th 2013, have installed U-verse TV. In the past, I didn't install cable TV, because I do not really watch television that much. Also, even though you guys sent those promotion mail that you will give me $200 worth reward card when installed U-verse TV. However, last Black Friday and Cyber Monday, I received e-mails that there will be $300 if I install the television during the Cyber Monday week, I would get $300 worth reward card, $200 and $100 bonus. That gave me eagerness to register U-verse TV, and by calling to 855-300-8942, which was written in the promotion e-mail, I installed the U-verse, and I also made sure that there will be $300 for sure before resister. That day was December 02, 2013 (Cyber Monday) and I'm sure it was recorded for monitoring.

After that, I was expecting to receive the reward card from AT&T.  But yesterday, I was trying to change the information for my credit card registered in AT&T because I recently received a new one, and when I logged into AT&T website, I saw the pop up that there is 200$ reward I received, so click and go to the reward center page and claim the reward. I felt something was wrong, because it should have been $300, and there, $100 became invisible, but still, I went to the reward center page to claim my reward. Then, what I saw was that the reward was already expired, because I didn't claim the reward between from the day I registered for U-verse TV and until one month after that day. I was surprised when I saw it, and I was mad by the fact that the reward card was expired because I didn't redemtion it in one month, because I never received any information to redemption it.

In my email, I am receiving how much the charges will be for the products I bought, such as mobile data, wireless internet, and this U-verse TV that brought a trouble, I am receiving promotions, but I am not receiving reminders for my rewards or warnings for expiration of claiming reward card. I was having a good respect on the big companies like AT&T that I believed, even though the cost is a bit expensive compared to other companies, the service will be worth costing expensively for the products. However, when I realized that there was no reminder and the reward card was expired without any notification, I lost the respect on AT&T. First, extra bonus $100 that was promised was vaporized; second, the $200 reward card was expired briefly. I am very disappointed to AT&T. When I looked at AT&T community, I saw that many people experienced similar problems I had in AT&T. I hope you to care and think about customers more. And if the reward cannot be granted, please tell me the way to cancel U-verse TV. I will look forward your answer.  Thank you.