So i bought the Arena REQ pack since there was a discount. It download fine, but once I started the game it didn’t reward me the REQ pack that are suppose to come with it. I understand we don’t get all of them at once. We get two per week. But I didn’t receive nothing. I wait to see maybe it was a delay. So I got on the next day and nothing. Contacted XBOX support chat to see but they told me everything was perfect. Now, Sunday, after watching the halo 5 championship, I download the free Halo 5 championship, open my game but I didn’t even receive it either. My friends all purchased the Arena and got it, but one friend also tried downloading the Championship but didn’t receive it either.
HELP!! Don’t want to lose that limited time REQ.
Do a hard reset of your Xbox and see if the packs show up after that. You can also check your unopened REQs here on waypoint through your Halo 5 profile 
I’ve had the same problem with the HWC req pack. I downloaded it but it doesn’t show up in the halo 5 menu. I’ve tried restarting my xbox and my internet, I’ve also tried uninstalling the req pack from the manage this game menu, then reinstalling it, but nothing is working. Please fix this issue 343 I really want that HWC pack.
Check the link below and see if it shows up there:
https://www.halowaypoint.com/en-us/games/halo-5-guardians/xbox-one/requisitions/unopened-packs
I found a solution for the HWC req pack. redeemed it by going to the xbox store online, like on the computer and redeeming it by there.
https://store.xbox.com/en-US/Xbox-One/DLC/Halo-5-Guardians-Halo-World-Championship-REQ-Pack/70ef0815-4488-44de-beed-d2852df07399
It doesn’t show up on the unopened-packs
and my code to redeem it from the purchase from amazon is already redeemed.