Halo 5 and Nightfall

It is realy weird . I watched through the 5 parts of nightfall and i neither get the nightfall helmet ,nor the armour, nor does the halo channel say , that I get my reward for watching it.
Can somebody pls help me because I realy want that helmet! (my Xbox username is Meloneprogamer)
Ps : thx for help

Did you watch all of it through the Halo Channel? There is a good possibility that the Nightfall promotion is no longer running. You can still get the Nightfall set through Gold Packs, though.