No Credit Needed just posted about his lack of internet at home. This reminded me about what happened to me last week. In an example of supremely bad timing, my internet went down for 3 days due to 'weather-related issues' when Alison and her houseguest... were MY houseguests. When it went back up, I called the customer service line, and politely asked for a percentage of my monthly bill to be credited, as they were not providing me with the service I was paying for. In about 15 minutes I got a $6 credit on my cable bill! That's about $24/hour. Not bad for something I can do while I am browsing the internet. Though I will have to be sure to double check my bill when it comes to make sure I have received the credit. If I don't I may look up some internet cafe rates for Boston and show them how much it could have cost me to go without internet for 3 days.
Moral of the story? Complain, but do it politely! If the cashier messes up(honestly Alison, complain a little more!), complain in line at the checkout. If your utilities company messes up, call a customer service rep and complain! Check your receipts, check your bills, don't let anyone cheat you out of your hard earned money.
Another thing to keep in mind is that everyone has different thresholds for complaining. Alison's Walmart incident didn't cross her threshold, but my internet-outage sure did! What is your threshold?