From Geoffrey James:
There are five words that every customer hates with a passion: “That is not my responsibility.”
From inside your company, you know which person and group has responsibility for various aspects of your business. Therefore, if a coworker comes to you with a problem that’s not in your bailiwick, you can send that coworker elsewhere.
The customer does NOT see your company that way. The customer doesn’t care a rat’s rear-end how your company is organized. All the customer sees is a person–you–who represents your entire company.
“Not my responsibility” is a phrase guaranteed to put you at odds with the customer. It instantly moves the conversation from you and the customer versus the problem to you versus the customer.
Even if it’s not your department, your area, your whatever… help the customer. If you don’t, they won’t be your customer for long.