FALSE ADVERTISING ON ONES PROPERTY

I woke up to a shock today when I was going out to work there is a FOR SALE BOARD on my outside lawn? my house in not for sale neither have I communicated to anyone about selling my house, to top it all the woman whose name is on the board is not answering my calls or returning them. when I called the Benoni office I was told one of the mangers will call me? no one has got in touch with me. The trauma this has cause to us as family. Who goes and put a FOR SALE BOARD RANDOMLY?