WHY TF DIDE HALO DELETE MY MAP I JUST MADE?!

Games Halo: The Master Chief Collection
#1

Worked super hard on a map all for it to vanish in thin air after i saved it and tied to play it. Y’all blow…
GET MY MAP BACK

#2

What happened exactly? You’re absolutely sure you saved it? Could you have maybe mistakenly overwritten another map?