Remember, the 'customer' is always right. [=never argue with a customer]
He is one tough/tricky 'customer'. [=he is a tough/tricky person]
The company has good/poor 'customer' service.
(..) All right. Wearing only this. The last thing l need... ..is another picture of me looking like a porcelain doll. As a paying customer... ..l expect to get what l want. Over on the bed... the couch. Go... lie down. Tell me when it looks right. Put your arm back the way it was. (..)1997 Titanic