Coffee cup half empty

It was a busy Sunday afternoon when a woman came through my line with about 20 items, including a cup of coffee. I rang up most of her order when she said, "I'll pay for this coffee if I have to but it was cold when I got it so I don't think you should charge me for it." Well, we're a small, local grocery store which happens to have cups of coffee for sale at the back of the store--so if she was expecting gourmet coffee or Starbucks she was just setting herself up for disappointment. But anyway, I was about to apologize that the coffee was cold when I happened to glance down at the cup and saw that it was well over half empty (well, maybe she was an optimist and saw the coffee cup as half full). Anyway, I thought to myself, 'Well the coffee couldn't have been that bad considering you drank almost all of it.' There was a line of customers behind her and I really didn't feel like arguing with this woman over an .89 cent cup of coffee. As I thought about it, it was more the principle of the thing then her not wanting to pay for the coffee that bothered me. Of course, a customer shouldn't have to pay for something if there is something wrong with it or if does not meet basic quality standards but it was fairly obvious that there wasn't really anything wrong with the coffee--she just didn't want to pay for it. And because it was the middle of my shift, and because it was busy and because I just didn't feel like arguing with her she got it for free. Even though it was just an .89 cent cup of coffee it just doesn't seem fair to everyone else who works hard, earns money and actually pay for the things that they consume.