As BCM has pointed out, under deposits I have inserted a clause requiring full payment on Booking and 100 % refund when cancelled before 48 hours. Unfortunately I lost money on direct bookings on seniors who I thought would not do this. By the way, it is a criminal offence and you should report this to Police.
On another note,Accom News reports that Booking.com and Expedia have been asked to remove the rate parity clause in their contracts as it is anti competitive.
http://www.accomnews.com.au/industry/154-news-in-brief/4981-ban-likely-for-ota-rate-parity-deals?utm_source=newsletter_707&utm_medium=email&utm_campaign=accommodation-industry-news-thursday-8th-april-2015-proof-1