Sterns Alberton unhappy customer

I'm not happy with the treatment I have received so far at Sterns ALBERTON.In October 2022 I bought a 9ct Necklace R2400.within 3 months that thing was brocken.took it for repairs and after 3 months it was broken again at the same spot. Because It took me almost 2 months to find the tillslip. I took it in for repairs because they said it was out of warranty they will charge me R1400. But I said to them this looks like a material problem as this keep breaking at the same spot.They said it didn't matter what made me mad was when the told me the Repair amount included polishing the necklace which had some plated gold. I was like what. I bought a 9ct gold necklace nothing on their stand spoke about this been gold plated. I refused to pay. I went to their shop this weekend and I realised they 9ct a gold That will last forever and when you have a problem they will say its gold plated. This is false advertising and I'm not happy. That necklace didn't even last 6 months and you call yourself a quality store I am really appalled.