Lying about a Rewards Card

I cannot believe what is happening with the customer service I'm getting from AT&T. Last year I signed up and was offered a rewards card.  A few weeks later I call since it hadn't showed up, and they tell me to keep waiting.  I wait some more, then they tell me I've missed my chance to claim my reward, and that I was not eligable for the reward. Great, so apparently the person lied to me, and they claim they reviewed the phone call and there's no proof.  The next year I go to complain and a lovely assistant helps me with  changing my service and tell em AGAIN that I will receive a rewards card in the mail. It must be too good to be true so I ask a bunch of times and she still says I will receive it, so I record the WHOLE CHAT that we have online saying I will get this rewards card.  Lo and behold, no rewards card.  I call again, and the same exact thing as last year, they tell me I'm not eligable for any rewards.

How is it possible that 2 AT&T representatives have directly lied to me and AT&T refused to compensate me in any way.