Not exactly the same situation, but still a phone number messup. A pretty large local online retailer managed to put my familiy's phone number on their payment due on their payment missed notice. Apprently they also messed their system up and send these notices to people who paid their stuff in time, so they were rightfully confused. For about three weeks we got a few hundred calls by confused and/or angry customers. Needless to say, I had quite a few interesting "conversations".