[joeysteele]

I don't make prank calls, however if I get those daft survey calls or a company I haven't contacted trying to sell me something I do often act like I cannot hear them and have them repeating everything over and over.
Or I ask them to fully explain the service or goods they are selling and then go and make a tea or coffee,leaving them talking away to no one.

I haven't a clue how long they stay on the phone when I do that but they are paying for the call so I get a bit of a kick out of that.