An auctioneer is advertising the house I just bought, even though the sale is fully completed! Is that legal?

I bought the place from a different agent, for way less money, and now this guy has knocked 8 grand of his advertised price a week ago! he's using 5 year old pictures from before the house was left derelict and i nabbed it. Surely this aint right? He's effectivle inviting poeiople to seek out and poke around my house!!!