"The customer is always right" is a classic customer service aphorism, but people who actually deal with customers tend to give each other knowing looks when you say it.
Customers are frequently wrong.
That might seem like an odd thing for us to admit, given how often we use the phrase "perception is reality". Surely that means that we have to treat customers' view as gospel?
Not necessarily. Customers are always right about what they think and how they feel. They're not always right about what happened, but neither are you. When there's a mismatch between what customers think happened and what you think happened it's a good idea to suspend judgement until you can figure out what's going on. In terms of what you say to the customer it's wiser, and fairer, to assume they're right and you're wrong to start with.
What customers are rarely right about, because they're not in a position to know, is what caused their problem or what you need to do to fix it. That's why customer feedback can rarely solve your problems for you, and why bad customer research can fail to deliver action.
To get from what customers say to actionable insight you need experience design, and that requires two layers of interpretation.
1. Insight = feedback + interpretation (of what causes customers to feel as they do)
2. Experience design = insight + interpretation (of what we can do to change it)
The customer's always right, but they don't have all the answers.