What if a Jewelry repair store loses your jewelry?

I hope you still have the slip they gave you when you gave them the jewelry. Those are important because sometimes they have statements in the small print. What did they say to you about your jewelry? I would give them 10 days to find it your item. Write them a letter requesting a refund and a credit or provide a replacement piece. Send the letter registered mail and keep a copy. If they don't respond within 10 days send a second letter stating your problem and that unless this is resolved you will take them to small claims court. When this passes go down and file a law suit against the store in small claims court. Make sure you take your letters, the sales slip, and any response from them to the court. If you have a picture of the item that would help and you may also get a placement cost for your item. The judge probably won't give you the cost of your item but you will get something out of this and not let the store get away with loosing your item.