I have a ring with a 6ct stone. One claw is loose. I've already taken it back to the seller twice & complained about the claw because I'm terrified of the stone falling out. I now have no confidence in them as they've 'fixed' it twice and it's no different. I also worry though about someone less scrupulous swapping the centre stone for one of lesser quality. How do I find a trustworthy & affordable jeweller to do a proper repair? The design is a one-off so the original seller can't offer a replacement.