It is possible they think you are churning. This sort of thing happened to me with citi. I have scores in the high 700s but citi will not give me another cc. And so its possible they think you churn too.
Now... On my checking app I can see a page now that says I will get a 10 + 15k award and so I'm not worried yet. Did you receive this page? If not did you apply correctly? And yet we all think and hope we did.
I can think of only one way out of it if cs doesn't solve it in your calls (and you should try the web team instead of normal cs) and that way would involve graphics and a hope their database can make errors whereas a few people slip Thu... anyway its not recomended.
Good luck...w web team.