Guest Scammer

[Liz54]

I recently hosted  a guest who I believe is a scammer.  When I checked out his most recent review (he stayed in Paris for three days) it appears he demanded some sort of refund from his host there.  After making a huge fuss about his apartment and noise during the day (it is an apartment within an apartment  clearly stated in the description) I was asked by ABB for a 33% refund for a months stay.  As a gesture of goodwill I refunded ABB £100 but made it clear this was not an acceptance of the complaints but as a Superhost for 14 years.  I was assured that the guest would not provide a review (by ABB in writing and by the guest).  Today he did so and jeopardised my Superhost status by giving me 4 and 3 star ratings.  ABB say he has the right to review and unless he says something unreasonable it will stand.  It appears I don't have a leg to stand on with ABB .....  This is the second time in all my years with ABB that a guest has been totally unreasonable and the previous time my Superhost status was lost for a year.  Any suggestions with how to get ABB to support their hosts better?