some fuck keeps ringing and hanging up. It sounds a bit like a little kid hitting the speed dial.
If you're going to prank call somebody, at least make it interesting. Earlier this year, somebody kept calling my number and hanging up as soon as I said hello (if I paused, I noticed they waited for me to speak), usually about 2-4 times a day for about a fortnight. I was more pissed off that they never did anything interesting than that they were calling me in the first place!