Staff member mocks customer with exchange

I went into Foschini this morning around 11 am and i was attended by the cashiers /floor assistant one in particular named Noghon had bad attitude she laughed and mocked me with her work colleagues because i had a garment purchased and with one wear and wash it shrunk as per the CPA law if anything is not of the branding quality i need to report and get an exchange how ever they made a mockery of me and told me there is nothing wrong with it . I had bought a lot of items and only wore this top of recent i had the receipts but still they treated me as an undervalued customer and some one who was mental.Is this the way Foschini wants their branding to be remembered with *********** and useless staff members who are good for just mocking customer and to top it off i spoke to store manager and she did not reprimand the rude staff member she played along with her.I need and exchange and an apology for the pathetic behavior the Foschini staff has.Wonder what else they do in store.