Green cross paint coming off the buckles less than 6days after purchased & green cross won’t exchange or refund me

Good Day - I purchased a pair of 3strap green cross sandals and noticed 6 days after purchasing it that the paint of the buckles were coming off. I have driven to Epping to show the manager the what’s happening to the shoe, she said that there is nothing they can do about it (very unhelpful) Then I called there customer care centre only to find that after another week that there is nothing they can do about this shoe. I mean goodness me I paid R929 for the shoe and after less than a week the paint starts coming off the buckles. How can green cross say at the back of there till slip that they “will gladly exchange or refund you” if the shoe was unworn , I have the original till slip and the box in which the shoes came in. They are hippocrates as all the above applies to me yet they won’t exchange or refund me. This is clearly a defect on green cross side but they aren’t willing to take the responsibility. I will NEVER EVER BUY A GREEN CROSS PRODUCT EVER AGAIN