Same here, I'm having the same problem.
I even un-linked my Call of Duty and Xbox Live account, and then re-linked them.
SO BEING a Tech Guy I figured Out That When The App Trys To Send Push Notifications To Your Account Via Call Of Duty. The Files Being Sent Are Stated In Game As "Corrupted" Meaning The Code being transferred between the app and Thru the servers to Players Accounts Are Being Jumbled And Faulty. Until They Release AN Update for the app it wont work.
And that might take some time to find what part of the code in the app is making it corrupted.
I Originally downloaded the app to both my iPhone and iPad. I had the emblem but I ended up selling my iPad. I restored my iPad before I sold it. Then the new Xbox One came out and I lost the patch. I currently use the app a lot for clan wars but I still don't have the patch. How can I get it back?
It seemed to take quite a while for it to unlock, but it did eventually unlock for me. It should be more instant than that, but the official reason for this is that it just takes time to unlock...