The story "The Exchange" by Jon Langford is a short story and it consists of only a dialog. The customer comes to the shop and asks the shop-assistant to replace a broken alarm clock.
It looks as his request is being refused by the clerk. All possible options for the exchange are dismissed because of different reasons (the customer doesn't remember when he bought the item, he didn't keep the original plastic packing and prove of payment. The seller concluded, "I wouldn't be able to do anything to help." The dialog further transmits the feeling of being desperate: "Nothing?" "No." "So now I just have a faulty alarm clock forever?"
The story turned to another, optimistic direction in the ending. Here the last part of the conversation between shop assistant and customer:
"Would you like to open a store card? It's completely free and you get five percent off every purchase.
No thank you.
If you open one today you get a free gift.
What's the free gift?
An alarm clock."
This story was on the top of reader's choice on the site for self published writers. I think that It deserved to be on the top, because the author was able to present the whole idea in a very short text, and even the mood and emotions of two characters.
This is the link to the story: