Think of yourself as a customer -- what do you expect from salespeople ... regardless of the circumstances and/or the problem. An example may be "Customer service is a two-piece reaction. First---respect; second -- problem solving." See if that makes sense and if you sound convincing when you do practice it. If you can give a brief story or two of what you have witnessed as extraordinary examples of customer service behavior. By using yourself as a focal point you will be able to enunciate clearly your understanding of customer service.