That’s the golden rule of customer service. But what if the customer is wrong? Seth Godin offers us this elegant insight: If the customer is wrong, they’re not your customer any more.
If the customer is indeed wrong (for instance they make egregious demands), you should politely decline to do business with them. You might as well since if you treat the customer like they are wrong, they won’t stay your customer for long. When customers leave of their own accord, they spread the word about the bad service you have provided.
The customer is never wrong, you just have the wrong customer. That’s why agencies fire clients.