Listen to the customer, understand his or her needs and wants, and do your best to satisfy the customer, in an ethical manner, i.e., don't sell your soul, in your attempt to satisfy an unethical customer. Remember that the customer is not the only stakeholder - you have a responsibility to satisfy ALL stakeholders, rather than the customer alone. Bear the foregoing in mind, when dealing with an unreasonable customer...and proceed accordingly. Good customers are like flowers in a garden - bad customers are like weeds, which must be eliminated from your database.