In the same way that you can’t please everyone in your personal life, you also can’t satisfy every customer in your professional life.
No service-provider has ever done that nor will any ever achieve that aim in the future.
Moments of miscommunication or mishap are bound to occur in any relationship. And sometimes your efforts to make things right may fail.
You can always learn from every experience where someone walks away unhappy with you.
Every failure to satisfy a customer’s needs is a lesson on how to get better at the work you do. Even if you don’t think you did anything wrong, you can always improve your ability to serve people more effectively. You don’t need to feel guilty in order to see an opportunity for growth.
Never let “But, I did my best” become a substitute for “I can learn to do better.”
Is the customer always right? Hell no! But the decision to listen and learn from them is.