Paul's dad: Hello!
Nick: Hello! this is Nick. Can I speak to Paul, please?
Paul's dad: Hello, Nick! I'm afraid Paul isn't here at the moment.
Nick: Can you tell him Nick called?
Paul's dad: OK, Nick, I'll give him the message.
Nick: Could you ask him to call me back, please?
Paul's dad: Certainly, Nick.
как то так вот