Re: Why so much anger?
"They need to get a grip on their misplaced anger."
So if your company has seriously mucked things up for a customer the customer should just shrug it off? They have no entitlement to be angry at your company, the one that's got things wrong? Why?
It may well be that anger is misplaced in that front line support isn't responsible for you company's lack of a proper escalation process, bad product quality, documentation or whatever it is that gave rise to the anger which may very well be justified. Front line support is, unfortunately, the only face your company presents to the user once the shiny suited salesman has disappeared.
But no company should regard anger directed at it as being misplaced unless they're very sure that it wasn't their own inadequacies that caused it. And they are, very often the cause in one way or another.