How the customer is treated on the phone generally reveals how the customer will be treated - period. Bad phone manners and technique usually are signs that the company or organization lacks a culture of customer caring. And, it normally starts at the top. Tame the voice-mail beast. Voice mail was meant to help businesses be productive, work smarter and be more accessible to those who count.
Customers certainly fit that category.
Use voice mail if you must, but change the message daily, check it hourly and return calls promptly. Always allow callers access to a live operator. Make quick decisions. Give authority to your personnel to provide instant resolution to a complaint without a slew of approval memos and an act of Congress. Clean up the shop.