Hello @Christo5
Frankly your host is lying to you. Of course if she cancels you would get a complete refund and a 10% uplift in additon to find something else.
Either there is building work going on during your planned stay and the host doesn't know that they can therefore cancel under extenuating circumstances. Or the host has over booked or wants to charge more and is cancelling your booking, but doesn#t want the cancellation penalties Airbnb imposes on them when you cancel as a host.
As you have already been in contact with Airbnb, call them again. They will be able to see that what the host has said on Airbnb messaging. Write back to your host and say that you have it confirmed by Airbnb that she needs to cancel and you will receive a complete refund.
You can call Airbnb via Skype or other cheap call services.
Let us know what happens.