I think she delivered clothes for a cleaners to an older man who hypnotized her. Multi-part story. He hypnotized her, and as she struggled to regain control of herself, she tried to counter his suggestions with self-hypnosis. However, she neglected to research the details and ran afoul of the subconscious lack of recognition for negatively-phrased statement. So recording herself saying, "You will not obey him," had much the opposite effect.