Appeal on wrong Invoice

Our property has received a non-guaranteed reservation while the property was accepting only non refundable reservations however we have still kept the reservation until 18:00hrs and cancelled the booking by notifying the guest and booking.com representative and explained them the situation that property is sold out. upon enquiring the booking.com representative said our geneious customer can make booking without credit card or any payment even your property is not accepting non-guaranteed bookings however the reservations was cancelled after 18:00hrs but wee have received an invoice surprisingly from booking.com mentioning that "we have relocated the guest and you have to pay for his accommodation !!!!! how is it possible.. we have sent an email but no respond as the wording used in thier email from customer relation was "The invoice for the refund is final, and this matter has been fully resolved for the guest. without listening the partner justification THEY MAKE THIER OWN DECISION !!!!!!!

1. You are giving us non-guaranteed reservations while property is only accepting no-refundable bookings with advance payment.

2. No credit card in guest profile to charge and secure his rooms.

3. We have still kept the booking until 06:00pm even property was sold out.  

3. At the end you ar blamig property for not accomodating guest and charguing us invoice.