Please help!!! Seriously... No XP!!

I have been playing halo 4 since the 25th of November. This game is getting on my nerves a ton! I was home sick today and was playing halo 4… i have not got any notification i hit the cap or any sort of “Message” at ALL, all of my friends are playing And gaining levels and i am not! I would really LOVE some help from a expert here. This honestly made me NOT want to play Halo anymore… And it was a huge let down that Microsoft couldn’t even help me out, i have called them 2 times now and i really do LOVE Halo4, one of my favorite games, i just don’t understand the XP limit, because i have never got it before, one of my friends… DHG Haloguy is rank 80 something and earlier was a 78… i just think thats a little unfair that i am being left out of the loop and other people can gain more xp than me. I had just finished my finals, played ONE ROUND… and got screwed over by 343… somebody please help me out here! Seriously, a 343 employee that can DO SOMTHING ABOUT THIS!!! Please respond to this!!! I HAVE NOT HIT THE CAP… (OR GOT A NOTIFACATION)