PLEASE REPLY:

As a business owner I would call the owner of the ring and explain the situation to the owner and let them know what is going on with their ring. I would call the person who purchased the ring and explain to them the situation and they would have to return the ring and get a full refund on the ring and then they could come into the store and get a discount on a new ring and give them extra incentives for purchasing a new ring from the store. I would retrain the employee and have the manager of the store properly inventory and put systems in place to ensure that rings are there for cleaning are put in a different area and/or labeled and kept in different area from what inventory is being sold.

If the person who purchased the ring didn't feel that they had to return the ring. I would make the employee pay back the price of the ring that they sold to the store and possibly fire them and the manager for letting this happen. There has to be some sort of personal responsibility of the sales person and the manager for not overseeing the ring being sold. The store's reputation is on the line for the mistake that was made. The original owner who brought the ring to the store to get it cleaned can tell every person they know what happen and go on social media and give the store a bad review. If something like this happens it will cause a negative effect on the business. If it's a small business it could face a situation that they might not be able to recover from. Not only is this an ethical decision on the store. The person who purchased the ring as to make the right decision and return the ring back to the store so it can be returned to the owner.