We all have different ways of dealing with poor customer service. As for me, I pretty much don't go back in most cases, although I do fill out the questionaires I am sent. I rely more on the positive side and try to make sure that I compliment good service. If I am in a store that has cards to fill out and a particular clerk goes the extra mile, I usually fill out a card with their name.
This brings to mind my St. Albans Messenger Motor Route Carriers over the years. For many, many years, a guy by the name of Pete Ashline delivered the Messenger. He used to drive a Volkswagon Rabbit and used to dart across the road and back so quickly that you could hardly believe he would finish his route without a major accident. I am guessing that over the past 25 or more years that I have had a Motor Route Carrier for the Messenger that I can count on my right hand fingers, the number of times that I have not received the paper. The Motor Route Carriers try to make sure you know who they are and I even had one guy who had car trouble and was unable to deliver the Messenger one day and he left a note of apology with the paper the next day. I truly admire this group of Motor Route Carriers. I don't know how the Messenger selects them, but they sure do a good job hiring them.
Below is the card that was with my paper yesterday:
(http://www.vtgrandpa.com/photos/albums/forum_photos/messenger_driver.jpg)