The band up/cup down really doesn't work. I have found that shop assistants stop suggesting it when you gently pull up on the shoulder straps and the whole thing rides up, flips over your boobs and then you take it off over your shoulders without stretching the fabric or undoing anything.
I got my first sports bra that was an actual sports bra that fit without me altering it last year. I bought all of them that they had in AU8B in the store. It's awesome! :D