i lost my monthly challenge xp

I played my last game for the challenge and got my xp .
After i turned off my box.
as i wanted to play i lost the rank cause 13000 xp were missing

Happened to me too. Very frustrating. Anyone know of any way to retrieve it or will 343 have to do some (unlikely) intervention?

This happened to me as well very annoying, i don not know what to do