Store is refusing to exchange

I bought a pair of shoes for R399 cash at woolworths 24/01/2015 i noticed and the peolpe that i work with noticed when i walk the shoe makes an annoying sound like it's made of plastic and I than took the shoe back to the shop and I informed them of my problem that I want to exchange the shoe as i am not happy with it they refused to exchange while i was at the shop 27/02/2015 and i was informed that they will take the shoes to the Technologist and they will call me once there is feedback no one called, i than called them 13/03/2015 to find out what is happening and i was told that the technologist found no problem with the shoes and the store will not exchange/refund me. what is frustrating is that Woolworths differentiate themselves as a store that MAKES A DIFFERENCE IN PEOPLES LIVES and that what makes them different FROM THE OTHER RETAILS SHOPS but with this problem that i am experiencing now Fathima at COST SERVICE told me that there is nothing they can do so i am stuck with the shoes that is a reject as far as i am concern. I GUESS THE 6 OUTCOMES OF TREATING CUSTOMERS FAIRLY IS NOT PRACTISE AT WOOLWORTHS SHOP.