3rd reward card canceled after accepting the reward

I placed AT&T fiber order with three offers. I received reward notification for all 3 rewards but only received the card for two rewards. When I called the rewards customer service, they mentioned only 2 rewards are valid for an account so the third is automatically canceled. This was never mentioned when placing order when talking to sales team. If I had known, I would have accepted only the higher value rewards first. How can I get this fixed? This is cheating customers with false hopes to get them moved from other service.