I do tech support for a cell carrier. Some crazy call types are:
Customers who are incredibly long-winded but still complain about how long they have been on the phone.
Customers who tell you their life story, turning a 15 minute call into an hour long call (maybe much longer).
Customers who are convinced that someone is spying on everything they do through their phone. Of course, I know this is true to some degree with Google, but I mean customers who have serious conspiracy theories and persecution delusions.