This is a 100% true story:
I worked at a software company, and the phone rang with a guy who had dialed the wrong number.
He was complaining about how someone had been out to fix his cable, but there was still distortion and it wasn't fixed. He was getting angrier and angrier as he talked and would not let me get a words in edgewise to let me tell him that he had the wrong number.
Finally, he ran out of breath and in the intervening moment of silence I asked him "Sir, I just have one question."
"Yes?" (cautiously angry)
"Why are you telling me this?"
Then he launched into a huge tirade about how he is paying so much for cable and how mad he was. I could almost hear the vien pop from his forehead over the phone.
Finally, he let me talk again and I told him "Well, sir, this isn't the cable company. You've called a software house. We don't have anything to do with your cable."
There was a moment of silence, then "Oh..." (click).