CVS once screwed up my wife's medicine pretty bad. She had to take blood thinning shots when she was pregnant with our daughter. It was supposed to be $50 copay for a one month supply, preloaded in needles. The store we went to charged her $150 for three needles and swore up and down it was per treatment. We contacted the insurance company and explained what happened, CVS gave our money back and apologized for the mistake, but we haven't used them since then.