@Joe71, the host made the mistake, so it is her/his responsibility to sort things out for you.
She could ask you to cancel with the proviso that you will be refunded the AirBnB booking fee by means of the Resolution Centre.
https://community.airbnb.com/t5/Hosts/The-Resolution-Center-A-Community-Help-Guide-Request-or-Offer/...
That way you won't be out of the pocket.
You might also want to contact AirBnB and ask their advice. Perhaps they can arrange alternative accommodation for you.
It's worth a try. AirBnB does not look kindly on hosts who don't keep their calendars up to date, or don't sync them with other home sharing platforms.
The UK number.
+44 203 318 1111