Bad service and product at Sterns alberon

I’m not happy with the service and the product I got at Sterns Alberto’s City mall . I bought a ring and within a week it changed it colour and the stone came out imagine, okay fine I took the ring back to the Alberton where I bought it and I told them that I want an exchange I can’t be wearing the ring that is not my size even after I took it took it for resizing and paid almost R800 for it to be resized, and now it changing colours and stones are coming out mind you it’s only been a week. They told me that I can’t exchange, I can’t get refund I spend more that R3500 on the ring on so annoyed and angry Sterns will just disappoint you as a costumers The manager was so rude and annoyed by me and my husband Sterns has lost me as a customer