shouting abuse and threatening to 'come and f*** my mother/sister/wife'. He was apoplectic with rage. It didn't help that his ranting caused me to start laughing and still makes me smile with satisfaction some weeks later.
I do this with Nigerian scammers. I get them to call me (expensive UK personal number) and keep them on for ages while I just make them repeat everything because I can't hear them properly, they run out of prepaid credit and have to go and get another card, etc ....... Eventually I ask them if they really thought I was going to fall for their pathetic scam ........ and then I get the comedy show and the abuse as above!