Hello @Chantal-And-Christian0
What issue are you contacting your host about that they are failing to respond to?
There is no cast iron guarantee with any holiday company that you book with that they won't cancel a booking. But I can see why if the host has lots of cancellations you would be concerned.
I have to ask if you know this host is 'known for cancelling his bookings' why you booked with them?
You'll know as an experienced host yourself, that if you decide to cancel the booking it will be in line with the cancellation policy you booked under.
If the host is failing to respond to you (you should keep all correspondence on Airbnb, not call), then I would call Airbnb and ask for their help.