Do you tend to give into customer complaints?

While it's important to keep customers happy, giving in to a complaint that could later be detrimental to the company you work for isn't right either.
Show the interviewer that you can be firm but still accommodating with this response: "What I do is I listen attentively to the customer's complaint and reassure them that the company will look into it. At my level, I cannot confirm resolution of the problem but I can let the customer feel that his concerns will be addressed promptly."