Can anyone tell me how to solve a problem I had with my Halo 3 achievements?

[Pepito]

I stopped playing on xbox live for about 2 months and when I got back online I lost all of my hayabusa armor and it said i did not complete the campaign on legendary when I did do it. I have the achievements for proof. Help me Please

 

[DunnDude]

that probably means your game file got deleted - if you or someone in your house was messing around in your memory on ur 360 you or they probably deleted your game file for halo 3 --- when you delete your game file your achievements stay on your xbox 360 - hope i helped

 

[DunnDude]

that probably means your game file got deleted - if you or someone in your house was messing around in your memory on ur 360 you or they probably deleted your game file for halo 3 --- when you delete your game file your achievements stay on your xbox 360 - hope i helped