Achievement Unlocks Faulty

Hey guys,

I just had my copy of Halo 4 delivered to me 2 days ago,and as soon as I started up the game I used the 12,000XP code in the Classified section of Waypoint,and I noticed that I didn’t get the achievement “Not Just Some Recruit Anymore”,which is the one that you get for getting to SR 5,even though I am currently SR 9.

Anybody else have this problem,or know how to solve it?