Okay so I took the time to beat the campaign on Normal first to get use to halo 5 Took a turn to do Hardest diffuculty completed it! & watched the cut scene at the end… no achievement unlocked & the -Yoinked!- up part is its gives me 93% for completion!!! what the hell 
I need help with this i would like to get the rest of my achievement score… called Xbox to see if they could help me & well low & behold they told me to reach out for the stares here… if anyone could be oh so kind to assist me in this matter it would be nice to see if there is armors in campaign & emblems or secret pack.
Here is a vid link of my proof of completing it:(below)
http://gameclipscontent-d2011.xboxlive.com/000900000c7c4060-24d904fb-3434-4fc4-bcfe-51ebcfa31021/GameClip-Original.MP4?sv=2014-02-14&sr=c&sig=FjMuXoBEsREPupMSBMWHw%2BHAiBAEpSD7XJwJoflLXeg%3D&st=2015-11-01T01%3A11%3A14Z&se=2015-11-01T02%3A16%3A14Z&sp=r&gda=1446344174_e3d540db8fd476c3454d32b9eafbf641