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.
(..) You didn't need this shit! You could've coasted on what you had goin'. Listen. I'm gonna tell you something I never told a customer before. Personally, I never made a bet in my life. You know why? Because I've observed firsthand the people addicted to gambling. What we would call degenerates. (..)1974 The Gambler
(..) - What's that? Fresh air. Open road. Free afternoon. Listen, I gotta see a customer for a minute. Wanna come along? Come on. You'll like this guy. He's nice. How long is this gonna take? (..)1974 The Gambler