The customer is always right - right? Is this your customer service mantra or do you think this is an 'old fashioned' way to think? Has customer service changed over the last 10 years or so? Should it?
I have run a couple of Customer Service Departments over the years and I always stress that if you don't at least start with this basic assumption, things will often not go well. When a customer calls with a question or problem, you simply have to give them the benefit of the doubt. Customer Service personnel should understand that they have the ability to make or break the company's relationship with its customers. You can have the best product, good prices - even fast delivery - but if people don't like you, they will not buy and they certainly will not recommend you.
So, is the customer always right? Of course not. I have actually found that the customer is often not right. Maybe they have the wrong information or caused the problem themselves. Customers can call to complain that their order was really late, but they placed the order a week later than they remembered. Someone may call to return a product that is not working and is 'brand new', but when you look it up, the product is 6 months past its warranty period. Customers are human. We are all customers at some point. Have you ever had a 'senior moment' when ordering something? Maybe you forgot to get your credit card out or changed your mind while ordering because you suddenly realized you did not really need to spend money on this item? Customer Service needs to take all of this in stride, keep their tone positive and work through the issues with the customer. The goal is to make the customer feel satisfied when the conversation (or email trail) is complete - even if they don't end up getting what they asked for!
Years ago, we often saw 'yes' people dealing with customers. "Yes, sir", "Of course, Ma'am" ... Pushing back on the customer was probably more frowned upon than it is today. Modern customer service works just fine with a little push back - but it must be under the premise that the goal is still to make that customer happy. It's ok to say "I'm sorry, but my records indicate that this was ordered in 2009, not last month" - here is the key to diffusing this, continue with - "Could I be missing something or was this ordered by someone else?" When questioning the validily of a customer's issue, always provide them with an out of some sort. Show them you are open to the possibility that you have not found what is needed or that you understand how easy it is to not remember when something was purchased - time flies in our busy world.
Nothing diffuses anger more than someone who is trying to share the blame for a problem and genuinely sounds like they really want to help you. This does not mean the customer will get what they wanted, but they need to feel like they got what they deserved in the end - even if that is simply having been made to understand that there is not really a problem after all!