Listening is an important part of communication, how would you be able to communicate with customer who doesn't allow you to speak in order to listen?

Speaking as an respond is not always must using words, sentences, or phrases. We still can respond customer's complaint, shouting, by our body language, gesture, and mimics. If all of that physical respond doing positively and properly, there will be timing for us to respond it by words, sentences, paragraphs,  even whole story that we need to tell nicely.