Rogue Agents using our flat listing

[Venus4]

Received a message today from one of our flat neighbours that someone turned up at the flat premises, saying she was booked the flat by an agent.  Which is not possible as we already have a guest staying there.  Said 'agent' was not mentioned or what company they were.  The lady was apparently just very irritated with the 'agent'  Seemed like a very calm reaction still.

We are based in a small town in England.  Last June 2016, there were 25 airBnB venues.  Now there are around 158 in our 5 mile radius area.  Unfortunately with the boom comes different types of problems.  Has anyone else had this experience?