Not me but a friend (honestly), we will call him Bob:

Background: He lived in a shared house at university with some guys and he had insomnia (he actually didn't, he just used to sleep from about 7pm until 10pm and then moan he could not sleep at night).

One of the guys cheated on his girlfriend and there was a bad breakup. Then they started getting silent phone calls at about 2am etc. Unfortunately Bob was awake at that time and just watching tv so he answered the phone. When the line was silent he guessed it was a crank call from his housemate's ex so rather than hang up he just chatted to the silent line. He would tell it about the TV program he was watching, what he had done that day, any plans he had for the next day etc. and just kept talking and running her phone bill up until they hung up. The entire conversation was one sided, she never said a word.

This happened several times until he actually started to look forward to it. Apparently watching The Incredible Hulk is more fun if you have someone to talk to even if they are not replying. Eventually she stopped bothering because she was spending money on her phone bill and wasting her time without bothering her ex boyfriend because Bob answered the phone so it did not wake anyone up.

Bob missed the calls so much he was going to phone her in the early morning instead and maintain the tradition.

Within a day he had a frantic phone call from her apologising and begging him not to phone her and tell her about late night TV and mathematics lectures!