Hello @Kamila31
I am sorry you had this experience.
Airbnb provides you with advice on what to do if your listing is not as described on your booking confirmation. Have you read this?
It says to contact the host about the situation - which you did . However as Airbnb advises you should keep all communications on their messaging systems - so there is a written record of any discussions between the host and guest.
They also tell you that if the situation can't be resolved you should contact them ASAP but definitely within 24 hours.
My advice:
1. summarise your conversation with the host and his rep on the airbnb message system - about the state of the place and their promise of a full refund. Take screen shots of your what's app conversations
2. Call airbnb now - they are open 24/7 - hopefully you have taken photos of the state of the property which you can share with them. Ask them to process a full refund as the property was filthy and not as described in the listing.
3. Leave an honest review about the state of place in the review
Good luck and do let us know how you get on.