I remember when I was a child, the worst thing I could ever do was lie. It didn't matter that I broke something, hurt someone or did something bad. It was only when I lied about it that I got into real trouble. Stealing and then lying about it was the worst thing I could ever do (I did it just once). Trust and honesty were indelibly inked into my personality from an early age.
That's why I find other people's behaviour so confusing. I don't understand when people misdirect attention away from the company and back onto the customer. I've seen individuals intentionally lie about faults, with a straight face, and not a hint of shame.
Don't do that. Don't lie to your customers. Your customers will eventually figure it out, no matter how stupid you think they are. Even worse, it will cause confusion in your own team. You know that fault you convinced the customer was their fault? Everyone internally thinks that it's been resolved too. So, when it crops up again, which it will, you've just wasted time, instead of buying yourself some breathing space.
Sometimes you might feel that you really, really need to lie to the customer. O.k. we'll have to disagree there. Even so, if you are going to lie to the customer, make sure that you don't lie to yourselves at the same time.
And understand, if I see you lying, I won't be impressed. I'll think you're an idiot and I won't trust you with anything.
Corollary - Every setting has a reason. If the default has changed, ask yourself "why has that changed?" Don't assume that it was done for no reason.