I had the most bizarre thing happen to me a few years back. The phone rang so I picked it up and said hello. The person then said "Who is this?" I replied, "Urm you phoned me, who are you?" She then got really snotty with me, and said that I had just called her, why was I calling and that she had used caller ID, so who's not so clever now. Completely astounded I had to tell her that I was alone in the house, had been all morning and no one had called her or anyone else for that matter from our number. It was so weird. She got a bit huffy, and insisted that our number was on her caller ID, I said that I was sorry but it had to be a mistake. We parted ways, and that was that. The only thing I can think was that she had noted down the number and had made an error in dialing it, I can't imagine the redial function on a phone would misdial, it was really very odd. Perhaps she liked to phone up random numbers and hassle them!!
I really loathe how people, when you answer the phone, ask you "who's this?" I always think that's kind of odd, don't you know who you've called?