Double debit

On the 12th June I made a booking through booking.com at Coastlands Musgrave and chose the pay now option for the discounted price. When I entered my card details and processed payment it went through as the normal rate. I then contacted booking.com and they asked for me to send screenshots which I did. I then received a call from booking.com and the consultant stated I do the booking again and she will cancel the previous booking. She canceled the previous booking but when I checked my card statement later that evening it reflected that I was debited twice. One debit from coastlands and the other from booking.com. I contacted booking.com on numerous occasions and even sent them an email and I still have not had any response. I am highly upset at the service received and will not be using booking.com again.