MCC Scarred armor set not unlocking in Halo 5!

I unlocked the Cairo Station achievement in the MCC in addition to beating the par score time as well. I was supposed to have the “Scarred” helmet & armor set unlocked. It’s been days and its still hasn’t shown up. I went through xbox support chat and followed the trouble shooting steps (removing my account, restarting etc.) Its still made no difference. The tech said it was on 343’s end and sounds like there is a bug or glitch involved. There is nothing wrong with my account. I have been advised to write in this forum to see if this can be corrected or if any other fellow gamers are having the same issues. Its just irritating being a loyal fan, grinding hours out into a game to not reap the rewards your rightfully deserve. So PLEASE 343 fix this ASAP. Thanks.