What's that song that starts out "Help me operator, get in touch with my Marie"? The number was written on the wall, or something. Even though it's never given, does that count? Title is about trying to ring Memphis, I think? Did the Big Bopper record that?

Or - on surer ground - there's that song from the musical Bells Are Ringing sung by an answering-service operator, which has the refrain, "I'm in love with a voice, Plaza 0 double-4 double-3..." All about how it's a poifect relationship because the two people involved don't know each other!