Unless they are wrong.
Then, the real question becomes, "How do you handle the fact that they are wrong, yet believe they are right?"
The answer to that question depends upon the horizon you have with your customers. Do you look at profitability as a requirement for each and every sale? Or, do you look at the long-term value of the customer spread out over months or years (multiple sales) as opposed to each transaction individually?
The answer also depends upon your customer-service mission. Are you customer-obsessed like Amazon, or are you more like Comcast where customers (even long-term good customers) tend to get in the way of efficiency and more profitability?
Take time to determine your customer horizon and your customer-service mission. Doing so will help you align your efforts with your message and be more authentic to those you wish to serve.