Disputing false claims in review from guest

[Claire2426]

I have received a very poor review from a guest., including aggressive and threatening behaviour. The guest had been declined a refund on their stay by Airbnb. I complained to Airbnb that the review did break their policy on several points to which they would not remove the review. I appealed against this and my appeal was denied. There is clear policy breaking in this review. Is there an external ombudsman that I could ask to take this forward? I live in the UK so not an EU member. Any help is very much appreciated. Thank you.