So my friend and me beat the campaign on legendary on halo 4 he got the armor for completing it but I didn’t whys that?
Did you do both the Prologue and the Epilogue? That may be a requirement. The campaign must also be completed when connected to Xbox Live.
Also, the armor is unlocked through the campaign commendations. If you check your commendation progress, and go to ‘campaign.’ it should show you what missions that you still need to complete if that applies.
Hopefully that should solve your problems. If that doesn’t work, then I don’t know what to tell you.
Your service record shows that you’ve completed all of the Campaign commendations. So if you didn’t have it before, you should now.
Sometimes people miss the Prologue and Epilogue, make sure you’ve done both, perhaps re-do them to be certain. Otherwise, double check and make sure you haven’t missed a mission.