What would you do if any customer complaint about your service?

To handle customer complaints you need to:

• Listen to the customer to figure out why they are upset. 
• Listen to the customer to determine whether any of your policies were not abided by or if this is something outside or not contemplated by your systems. 
• Next put yourself in the shoes of the customer. Given what you now know try and see their point of view. Why did they come to you? 
• Once you have heard the complaint and understand the basis for the same, elevate the customer to a supervisor or manager where possible. 
• Defend if you must. But do not fight with the customer.
• Once you have listened and understood the customer’s complaint and have avoided fighting over the same divert the customer’s focus to how you intend to resolve the matter.
• Use customer complaints as a manner to learn about potential flaws in your systems. Maintain a manner of tracking customer complaints .

If you are aware about all these steps then you will not face any problem in answering this question.