Sterns in Kathy are selling defective jewlery and won't give your momey back

I bought a gold chain with a gold and silver pendant with stones on the 27th of June 2020 from Sterns in Kathu for R1199.00. Now 4 months later the stones are falling out and the gold is coming of. When I took it back on Sunday requesting my money back I was told to come back the next day as the manager wasn't working that sunday. So today I went back and again no manager assisting me; only the same lady as yesterday. But now she tells me the pendant are not included in the 6months warranty but they can sent it in to be resprayed at my own cost!!@ I told her that there is no way that i'm paying as I was not told that I was buying junk that will discolour every few months and that gold plated should not come of otherwise i would not have bought it. She then called a guy by the name of Gert who said she must sent it in for quality control. Do they not even know the quality of their products? Now she said it will take 2 months before they will call me. It took them 5minutes to take my cash@!@ I only wan't my money back as they sold me ****. Please help