Like many other profession, customer service jobs have work ethics and rules that must be obeyed. With this, stick to the complaint procedure. Tell them we don’t need to rush things and submit complaints to highest official. Instead, approach the team leader first, the administrator and so on.
Countless potential customers in retail shops go unnoticed every day. It is often this attitude of indifference that leads people to shop at other places. Make sure that you have a candidate that will meet and greet your customers. Interviewees, let your personality shine here. Let your interviewer know that you are not afraid to introduce yourself to customers, and that you will not be hiding in the back restocking something.