I occasionally have to talk to customers about their problems, and when one of them gets like "Cherry Bomb", my fault or not, for some reason the phone just goes *click*

They're almost always nicer when they call back. And so far, they've always been nicer if they have to call back yet again (You'd be amazed at how nice a Cherry Bomb can be if they really want to get their invoices posted at end-of-month).