Rude manager and bad customer service

Yesterday I bought a dress at umtata bt ngebs mall,the dress was dirty and I reported the matter but the manager said she won't give me any discount i must buy the dress though it's dirty cos it was not her fault and I can go buy from other stores if i want but she won't discount the dress she even said "get out of my store"her name is Luleka she is very rude and doesn't have customer service