Back in the days of pheasant-under-glass mainframes, I had a part time student job as an operator in the computation center. We had a phone at the operator console, and 90% of the legitimate calls came from the operator console at the computation center at the other state university on the other side of the state. Our phone number happenned to be the same, but for the middle two digits reversed, of the most popular pizza place in a college town. The vast majority of the calls were to place a pizza order, not someone looking for the on-duty mainframe operator.
Our standard practice was to answer the phone “wrong number” — because it usually was. Anyone with a legit reason to call us knew the drill. Pizza orderers, especially the half-drunk ones, were our amusment on an lonely night shift of hanging tapes.
Called the pizza place and it took them quite some time to understand what could have gone wrong. I had, after all, logged in, and was still logged in. We had a good laugh when we figured it out. Sales rep called the guy up, but I don't think he cancelled the pizza. So free pizza, I guess.