Halo 4 Mk.VI Armor Issue

I got Halo 4 on Christmas, as well as a new Xbox and Xbox Live Account. I then proceeded to beat the campaign on Legendary difficulty with my brother (we do this with EVERY Halo game) and I didn’t receive the Mk.VI armor. I didn’t mind, I don’t care much for the armor itself, but I’m a completionist, so I checked why I didn’t get the armor about a week ago. Something about Waypoint didn’t register that I completed the first 4 missions, so I went back and played the first 4 on Legendary (alone this time). It was difficult and I died a lot, but the real issue is, I got to Infinity and my internet connection dropped near the end of the mission, and I got it back up and connected during the mission, but after the mission was over, I didn’t get the armor. Waypoint still said I hadn’t completed the 4th mission. I completed it, with 12+ deaths, and it took me 2 hours (stupid Crawler Snipes and EMP Grunts).
So the problem is, I’ve beat this mission twice. I’m sick of it. Legendary difficulty isn’t fun for me, the deaths get irritating. So is there any way I can get this stupid frickin armor without having to beat it AGAIN? I could do co-op with some buddies, but my internet connection SUCKS and lags really bad in online co-op, and my brother doesn’t want to play it again either.
Do I have to beat it again, or no?

> So is there any way I can get this stupid frickin armor without having to beat it AGAIN?

Unfortunately, no. You gotta beat the mission again – and without disconnecting during your playthrough, it seems. :\

Watch some Youtube guides, legendary walkthoughs, speedruns, LASO. Sometimes you can find some really nice tricks and skips.