Well, we don't do "do overs" and we don't apologize for anything short of a factual error on our part, so they didn't get their wish. The cool thing was, they sounded happy when they hung up the phone with me.
To be honest, I almost enjoy dealing with unsatisfied customers. I think I'm pretty good at it. Someone gave me the heads up that those two would be calling tonight... and the suggestion was made to "rip 'em a new asshole." But what good would that have accomplished? I listened, let them vent (which is really all they want to do) and then I established a firm stance, justified it and stuck by it. I saw where they were coming from and I explained where we were coming from.
Certainly, my plan doesn't work all the time... but I'll put its success rate up against asshole ripping any day. And when it does work, it makes me feel pretty good.