Overheard the customer ahead of me in a shop today... he was returning a jumper he had bought for his wife for Christmas for a bigger size in the same jumper. He had paid £59 for it before Christmas, but it had now been reduced in the sale to £39.
The shop assistant at the till called for the manager to "do a refund". Manager came over, did the exchange on the till, handed customer the bigger jumper and his receipt. Customer queried the price difference as the transaction was now apparently complete but he hadn't received the £20 difference back. Manager explained he hadn't realised there was now a price difference, having thought that it was "just a straight swap", however that it wasn't the company's policy to refund the difference in the situation.
The customer wasn't happy with this and said he had never experienced that approach in any other shops before; normally the difference would be refunded. The manager did end up relenting and refunded the £20 despite it not being "what they normally do".
It got me thinking... would you expect to get the £20 difference back?