Now, When i first got reach i earned 2000-4000 cR per firefight/campaign mission, but one day my internet connecting to my xbox went out for 4 days, when it finally got fixed, i only got 60 cR per mission, why is this ( i do have GOLD)
Are you playing them in the Campaign and Firefight tabs? Because that is offline, where you earn cR at a very reduced rate. If you go into matchmaking and go into firefight or Campaign from there you will earn plenty of cR