iStore don't train their staff - you pay

I bought my daughter a brand new iPhone AND MacBook at iStore @Woodlands Pretoria East. The sales person manage to also sell me a Thule hard cover for the MacBook to ensure its protected. After spending R2000 on the cover we later discovered that the MacBook does not fit in the cover! I don't have the original packaging, and they refuse to take it back... I pay because Apple iStore don't believe in training their staff.