How are you farming super credits? I would love to make 400 in 2 hours, are you just playing low difficulty missions and rushing the bunkers and stuff?
Difficulty 3 on robot planets with good visibility is my preference. I think it's because there are fewer items in the loot tables in 3 so I run across super credits more often. (I'm not who you responded to, but figured I could chime in)
Any super credits or medals you or your squad mates pick up during a mission are immediately added to your account. Unlike samples, you do not need to extract or even finish any objective to keep them.