Nonverbal messages are likely to be highly ineffective in customer interaction clearly indicate that words have little relevance are likely to contradict or override verbal messages replace written communication in business

I believe the answer is: are likely to contradict or override verbal messages

On average, people pay attention to about 70% of non-verbal message and only 30% of the verbal message for example.
For example, if the verbal message contain a sentence such as "you're so stupid!".
But the one who said it do it while giggling, laughing, or  throwing playful gesture, it would most likely wouldn't be interpreted as an insult.