i lost my monthly challenge xp

Games Other Halo
1

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

2

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

3

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