First, identify the source of the problem. Try to find out what is the problem and apologize about the current situation. Depending what the problem is you can do one of the following: If the price of the item is different from what's on the shelf, find a way to make sure that the item is matches to what the customer saw. If there is a item that is empty on the shelves, find a substitute or if it's on sale issue a Rain Check on the item.