@Bernadette50
I'm surprised you don't know that all of your listings are on Instant Book which means exactly what it says - can be instantly booked without your permission.
Have you never looked at your listings on the site (click preview on edite page)?
You might find it useful to inform yourself about how the system works. This forum is a treasure trove of all kinds of questions, esp. also Instant Book (IB), and you can search in the search field for such threads. And make sure you keep your calendar updated.
The invested time is well worth preventing cancellation penalties.
Good hosting.