Of course you should treat all customers well, but not as though they're your "top" priority. Ironically, several consultants I've worked with (from major firms) suggest that's actually a mistake, because acting that way can cause clients to distrust you. Clients know very well that they're not your only client, or "best" client in most cases, and if they think you treat everyone like that, it can hurt your credibility.
As for refunds... no, you shouldn't always give a refund just because they object. That depends on what you're providing, and why they object. If they're simply one of those clients who will never be satisfied with anything, that's not your fault as long as you make an honest effort to meet all of their needs, and you thoroughly interview them up front about what they wanted. Also, clients who repeatedly delay projects and change their requirements don't deserve refunds in a large number of cases. That's also the reason why kill fees and similar things exist. A refund isn't a cure-all, and can make you a pushover if you do it too often. You have to know the difference between that and running an ethically sound operation - don't take advantage of clients, but also don't let them take advantage of you.
And in the end, no, the client is not always right... sort of in line with what topic said. There are a large number of situations where business owners, freelancers, and consultants are completely justified in "firing" clients, and most successful ones independently or in large firms do this regularly in addition to rejecting them from the start.
The problem is the customer is not always right, so that is a horrible cliche and should not be the foundation of any business. You always want to be accommodating to your customers but saying they are always right is wrong. Nobody is always right, most especially your customers. So sometimes you have to go out of your way to help them, even when they are wrong.
Treating customers well under your baundaries is not bad. As every business runs due to the number of clients he posses. So every business man who wants to achieve progress then he will have to watch the needs of his clients, after all they give you the huge part of your profit. And also need some extra care. But again I want to say under your limits don't try to help them beyond your limits that will not gonna help your business to progress but may go in trouble.
Customer is always right untill he understand the business baundaries.