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.
(..) Like it? He'll love it. Yes, Hephaestus does do quality work. Everyone else these days, hacks. Excuse me, we're looking for Hermes. I'm sorry to be the god of obviousness, but I'm with a customer. You want an overnight shipment to Hades, that will be drachmas. Perfect. Thank you, sweetness. (..)2013 Percy Jackson: Sea of Monsters