If you get an autodialler, hit the # key 5 times, it reckons you are a fax and never rings again
My personal favourite is they ring for missus name, and when I say she is out they say can we speak to mr X and I say very clearly there is no Mr X they always ring off.
Although one today peed me off enough to get hung up on. Was a cold call from a separate company offering "benefits" as I am a valued cardholder for an unconnected company, I told her I wasn't interested and was at that moment balancing a TV, which indeed I was and she carried on twice so got the end button
