If you want to be a good customer service, the most basic premise is that you should articulate clearly and express logically, at least let customers understand what you say. In this regard, there are special teachers to train every month after joining the company.
When the customer's words are extreme, it is good to make the customer embarrassed to find trouble with the company. In fact, as long as he knows enough about the company and products and is good at communicating and coordinating all aspects.