I had the same issue too. I got the 40k offer with $100 statement credit. I got the miles right away, but the $100 credit never showed up. I just kept on calling. About the 4th time I called in the span of 6 months, the agent offered me extra 3000 miles for all my troubles. That was nice. And to top it off, instead of a $100 credit, they eventually gave me a $200 statement credit. Good luck.