Gustavo Marinho

Today i got halo 4 and the multiplayer was great i was playing with my friends and everything then later today it de ranked me to level 1 then said i was unable to play multiplayer and i couldn't join any of my friends games. When i press start it shows me my real spartan and his real rank but online it doesn't any body else have this problem and if you do is there anyway to fix it or get in contact with 343,