With the question “how would you handle a customer complaint?” always make sure you listen to the problem your customer is having, do not interrupt while he/she is talking to you as that will just annoy them further. Once they have finished explaining, make sure you apologise, let them know you will make it your responsibility to make things right and solve their issue. Doing this will make sure the customer is happy with your help, and make them come back to the store in future.