I've been in the Customer Service line for the past 10years+. Though I cannot declared to be 100% professional, but I do know what are the basic expectation of a customer service. Below is my definition of a Customer Service in my own words based on my past experience.
Customer service is:
1. Listen with EMPATHY and turning a DEAF ear to customer’s screaming and shouting.
2. Keep your head COOL when all the scolding has spoilt your day first thing in the morning picking up the call from customer.
3. “SMILE” and pacify the customer (even if this is over the phone); the other party may not be able to see you, but they can “FEEL” you.
4. PATIENCE! PATIENCE! PATIENCE! PATIENCE is what you need, especially when customer gets so agitated that they simply refuse to accept any of your explanation.
5. Follow through and offer solutions to show you CARE.
6. Making FRIENDS with your customer, understand their needs and position and they will reciprocate the same. It is just the same theory as respect others the way you want to be respected.
Feel free to add on what are your expectation of good customer service :)