Twice in the last twenty minutes my mobile phone provider, Singlepoint, has rung me touting for more business. I turned down the first one, of course, and interrupted the second one before he got too far into his spiel. He then tried to carry on!
“Are you not interested in saving–?”
“I turned down the first one twenty minutes ago, and I’m hardly likely to have changed my mind in the time being.”
“Not even to–”
“Look, I know you’re just reading whatever your system tells you to, but I’m really not interested.”
At this he finally gave up. Time to register with the anti-phone-spam people. Sadly it takes “up to 28 days” to be effective.
Avaragado's blog 
And again
Third time… at least this chap had the decency to apologise and not run through his script.