I listened to the Comcast representative call on soundcloud recently, and although it was infuriating, I couldn't help but start laughing out of sheer disbelief. Other things that seriously aggravate me may lead to me laughing in exasperation, but I don't think of "exasperation" as necessarily including laughter. Is there a word for this kind of laughter, or for anger that is so intense that it causes laughter?
This could be a form of manic laughter, which happens when someone is just too revved up that the laughter spills out of them.
If the exasperation that boils over into laughter is scornful or mocking, it could be called sardonic laughter.
But when it’s the kind of thing you see in cartoon caricatures of evil characters, then it’s maniacal laughter.