When are they going to be given out? I it has been five days since the challenge has ended.
> *To receive avatar item, you must play Halo 4 standard edition and achieve a CSR rank of 35 or higher on the Castle Team DLC Playlist while connected to Xbox LIVE, any time between April 8 2013, 2AM PST and April 22 2013, 2 AM PST. A download code will be sent to your Xbox LIVE messages inbox associated with your Xbox LIVE account by May 13, 2013; limit one avatar item per gamertag.
http://blogs.halowaypoint.com/Headlines/post/2013/04/09/CSR-Challenge-.aspx
Between April 8 and April 22 you will get the code
Edit: I had not seen The Little Moa’s post 