The major investigation that is launched at my big three retailer starting with M whenever you bring a receipt to "customer service" after checkout showing that you were overcharged the displayed price. Long, long, perusals of the receipt where the error has already been circled. Pow-wows called with numerous people attending. Much quiet hemming and hawing. More staring at the receipt. Long, long foot dragging. Multiple photocopies made of multiple documents. Outgoing phone calls. (Bangkok? The Prime Minister?) After waiting an inevitable 20 minutes you will somehow get your money back, but what you will never, ever get is an apology.