Good customer service starts with being friendly and polite. You need to put the customers’ needs first. This arguably the first step of creating loyal customers. On graduate job descriptions this skill can be phrased as ‘good client management skills’ or ‘the ability to build constructive relationships”. Not all customers are alike. Some will actively seek out help when needed while others may simply walk out of the store out of social anxiety.
As a sales assistant it’s on you to ensure each customer feels welcome at the store. Nobody wants to do business with a person they find rude or unpleasant.
This means you as a sales assistant must always bring your A-game when dealing with customers. When dealing with customers you need to maintain a polite and sensitive approach regardless of the customer’s attitude. The bottom line here is, there are rude people in the world and as a sales assistant you will definitely come across quite a few.
Whether the individual is ill or well behaved should have no effect on your course of conduct. Keep your slate clean and the unpleasantry will see itself out.