Hello @Nicola379,
That's not normal, acceptable and is against Airbnb's terms.
The conditions, amenities, house rules, price etc. existing at the time the reservation is confirmed form part of the contract.
If you decline the adjustment request the reservation and price stay as they were. That is, the reservation will still be valid and so will the original price.
If the host can't honour the dates or wishes to charge more because they hadn't set their pricing that's their problem and they have to cancel if they don't want the reservation. Of course they will be reluctant to do that due to the host penalties for cancellations.
If it comes to it and you feel that staying would not be comfortable you could send them a request to cancel. To do this you go to your trips, select the one concerned and click on "Change or Cancel" and select "Cancel" and then select the reason "My host needs to cancel". If the host declines the request everything stays as is but if the host accepts or ignores the request they will be deemed to have cancelled and you will get a full refund of accommodation charges and Airbnb guest fees.
I would report the listing and host by clicking on the little flag on the listing page and on the host's profile page.
Steve.
