Disgusting service and ********* policy compliance

I took back a maybelline foundation at Dis-chem Cresta that was given to me by a assistant and suggested the specific color because there was no tester, they didn't want to exchange it for me rudely saying its against company policy because it was open but if there was no tester and a dischem makeup assistant gave it to me clearly there should be some sort of compensation, both managers were non helpful and rude said i should take it up the the assistant that helped me.