Legendary Campaign Problem

I completed the halo 4 on legendary solo today, so I checked the armoury for the mark 6 armour it wasn’t there!
I played the last two levels of it offline because the internet would not connect and it didn’t register them!
So am I going to have to replay the last two levels again when I get the internet sorted on my Xbox or is there a way of showing that I Have completed it on legendary Solo

Please help if you can.

Yeah you gotta be online to unlock that stuff. SO your gonna have to redo those two levels again

yeah same thing happened to me in reach. moved into new apt, didnt have internet yet so i was bored and decided to beat legendary on solo, when i got internet finally and i logged into xbl…didnt register, had to do it all again