Back to Work Related 
Offering quality customer service involves meeting two important challenges: doing the job right the first time and having a plan in place when thing go wrong.
There is nothing more important to the customer then keeping the "promise of service." Customers want businesses to do what they say they are going to do. Be responsive, be professional, and most of all . . . be reliable!
The best system in the world for providing customer service is also the simplest. Do what you say you are going to do, when you say you will, and do it right the first time. You know you're on the right track when customers start expecting you to get it right every time.
Despite doing your best to ensure that nothing goes wrong, occasionally something will. Because often the way your customers judge you is by what you are willing to do to correct your mistakes. The first thing the customer must know is that you sincerely regret making the mistake. Whether you see it to be a big deal or not, it's always a big deal to the customer.
Your goal should always be to do whatever it takes to keep the customer coming back. But when someone is trying to take extreme advantage of you, you may have to evaluate whether salvaging the relationship is worth it.
If you've decided to do what the customer wants you to do to correct the problem, do the job completely and cheerfully. Don't haggle over the cost or be sarcastic. If you are anything less than congenial and cheerful, it will cost you all of the good will you tried to establish.