Here are Sewell's Ten Commandments of Customer Service. Bring 'em back alive. Systems, not smiles. When the customer asks, the answer is always yes. Fire your inspectors and consumer relations department.
Salaries are unfair.
Your mother was right. You have to make money to stay in business and provide good service. Sewell wants to make each customer a customer for life. He has actually underestimated the value of the customer because of the potential referrals the customer might make. Read this book.