Thats awesome.  You'd think that your answering machine message would've given them an idea that it was the wrong number. 

Surprisingly, people can be pretty dumb!  I ALWAYS answer the phone at work by saying either thanks for calling *** - or - boat shop, NATHAN speaking, how can I help you?  9 times out of 10 the response is either "douglas?" or "mike?" - noooooooo, this is NATHAN!