I once had a gripe over a $35 overcharge on a medical bill (too many details to explain here). After a lengthy, unproductive telephone dispute with a (very rude) customer service representative, I was no better off than when I started.
Angry and frustrated, I got some names and wrote a polite letter to the head administrator of the hospital. I pointed out why the hospital policy was flawed (resulted in double billing), but that it was not the dollar amount that bothered me as much as the rudeness and condescension with which I had been treated by their customer service dept.
After that, I felt much better. I had almost forgotten the incident when a month later, I received a letter of apology from the head of the billing department and a refund check for the $35 overcharge.