I had something similar happen with a house I had for sale. I was selling one of my houses and had someone knock on my door offering to give me the "full price". Unfortunately the house I had for sale was at a different location than the phone number. The person who came to my door thought they could buy my waterfront house for 149,900. The house for sale was at another location. I never authorized anyone to list my house on their website.
I'm glad you gave everyone this warning.....