Defiant Map Pack Fail

So I downloaded the Map Pack from the dashboard, but the game still reads I have to buy it. What’s the issue?

I had the same problem too but i fixed it

First do you have a 4gb xbox or something else?
Do you also have the Noble Map Pack?
Do you have Bungie Pro?
Anything else like Downloadable armor (recon)?

I solved the problem already thanks to a sticky on the Bungie site with Map Pack FAQs (which by the way 343 you need to get). The problem was my Bungie Pro Confirmation.