Didn't receive the $50 reward card as promised

I switched from xfinity to AT&T fiber earlier this month. During the checkout, a popup window showed up saying they can give me an extra $50 reward card if I use their service. That would be two reward cards ($100 + $50). After a few days, I did receive the email to claim the $100 card, but never the $50 one. I called the customer service and was told my account never had a $50 reward card. That's disappointing because you didn't get what was promised.