Here's the biggest lesson for everyone who's serious about learning to Love Your Customer... Never tell them they're wrong!
Ok, so what I'm NOT saying here is that "the customer is always right" - because they're not always right... and I have to say "I Really Hate That Saying"
An example of how poor this saying is, would be that they - the customer, don't know everything about how your business operates so they therefore can only see things from their perspective... which is only 100% correct to themselves.
It's only when you've told them they're wrong that it makes them right and you just F'd up the relationship for good by saying that they're wrong.
How I learnt this stuff
I first discovered the power of "Never Tell them they're wrong" about twenty years ago after reading the classic How to Win Friends and Influence People - by Dale Carnegie.
Follow this I had my first taste of dealing with an irate customer and instead of being defensive (my normal mode at that time) I listened to them rant and then used the magic words... "I'm Sorry" - in fact my exact words were "I'm sorry I didn't mean to upset you"
Talk about break-through, I very quickly realised that it wasn't personal and they weren't upset at what I'd done (or hadn't done) as it was something completely different because they changed the subject and started complaining about other people who I'd never met before.
My big lesson was never react and never tell them they're wrong - in fact I made it a policy in my business for myself and all my team.