It's relieving that someone else only did the cost of sales part. I talked to my teacher afterwards and they said unless a lot of the markers agree that what we did is correct/acceptable, odds are we will only get 1/5 or 2/5 which I think is completely unfair 
oh that's interesting, that there are teachers agreeing the full effect of a sale return should have been recorded. it was a pretty bad question to cause this much ambiguity.
Thanks for answering!
Do you think it could go below a 30? I'm just thankful that my grades this year in SACS will help me
Probably not below 30, you'd be surprised how low some people can score. Are you sure you only got ~50%? like sometimes when you over think things you can feel that you did worse than you actually did, it's quite unlikely to go from A in SACs to just passing in an exam if your SACs were of reasonable difficulty.