Courts are loathe to accept, "They made me do it!" as a defense. So, why would it work in client service? I don't think it does.
"It is our policy..." Does that ever work as a response to a complaint? I don't see how it could. Someone said this to me the other day. Not only did it not respond to my comment, but also, if anything, it just escalated matters.
I felt frustrated. I was making a point that she never acknowledged. She was like a child who got in trouble on the playground, pointing the finger elsewhere. That's client disservice. It also assumes, wrongfully in this day and age, that others will contain themselves better than she did. It's a dangerous gamble.
When someone believes in you enough to bring something to your attention, take advantage of it! They are saying they think highly enough of you to expect you to be able to handle it. Don't breach that trust.
If you stay in the conversation...if you actually show up, you have the opportunity to shine and build an amazing professional relationship. What better client is there than one who is very clear on expectations? And who better to draw those out than you, an expert in your field? And there is no better time to have that conversation than when something isn't working.
We all know the temptation to just let things slide when we are comfortable. But good enough isn't good. Dissatisfaction is the mother of inventions. So, Expert, be the inventor!
Now, in order to be the inventor, first you need a good understanding of the gap between what the person experienced and what they want. And when someone is upset, they'll do that at least part of that work for you. All you need to do is listen and have a conversation.
Most people aren't trained in how to communicate, much less when there is dissatisfaction, though. So, they resort to the factory default setting: react. They either react passively or aggressively. Neither of those puts you in a good position.
You have the opportunity to respond, but first you need to listen. That's listen to understand, not reply. Until you do, you can't respond; you don't have anything to respond to.
Listening isn't the be all end all of the conversation. You need to share your perspective and have some discussion, too. If you start with listening to understand, though, you'll save yourself a lot of time, increase your safety, increase your own satisfaction, get better results for clients, stay safer in the event of conflict, and save a lot of money on marketing and public relations.