Customers expect single source service. Customers don't want to be transferred to every unit of your business to have their problems solved. They want to be able to do business with you with the slightest amount of discomfort. You must be easy to do business with. This means taking ownership of your customers requests, problem, etc., and ensuring that their needs are met to their satisfaction.
Customers expect superior communication.
They may not be the best communicators, but they expect communication excellence from you. So, if you tell them that you will call them back at a certain time, make sure that you do. Your responsiveness will create a bond of trust, and a communication comfort level. Customers expect consulting. This will demonstrate your ability and knowledge as well as your intent to spend the necessary time with them to meet their specific needs.