No show Guests Told Booking.com they come to our Place

Hi Mates

I have few No show Reservation but i never got partial paid and one night got an email From Booking.com state that the No Show Guest come to our place but they never did and what should i do and how can i track this kind of guest because they need to pay their No show reservation but they Credit card status Invalid

and also how come there another listing of my place run by other people without known by me how come booking.com publish duplicate property without clarification 

Please help me thanks