STERNS SELLS EXTREMELY POOR QUALITY PRODUCTS

I got engaged in April with a ring that we bought at Sterns Bloemfontein in Mimosa Mall. Received a verification certificate that says the ring is 9ct white gold. We had the ring made smaller a few days after the engagement (by themselves) and 3 months after that it started to turn yellow/gold on the bottom side, and the longer I waited the further the yellow spread. I went back to them and told them that I was unlucky where they just shrugged their shoulders and said that white gold does that and I just have to do rhodium plating. I went and had the rhodium plating done and 5 days later the yellow stated to show up again. I am very disappointed and will never do business with them again. Probably the worst service I have ever received. People be careful if you buy from Sterns, their quality is extremely poor. I talked to a bunch of other jewelers and none of them told me that white gold wears off and turns yellow. THIS IS UNACCEPTABLE, AND ALL THEY DO IS JUST SAY WE CAN'T DO ANYTHING ABOUT IT, I PROBABLY WORK TOO MUCH WITH MY HANDS AND THAT'S WHY THE (SILVER) IS COMING OFF THE RING, DON'T DO BUSINESS WITH THEM!!!