Double billed for a cancelled booking

Ridiculous!!! I cancelled a booking, was then charged for it. Luckily the hotel said its fine i can cancel and they sent me a cancellation request which i accepted. And instead of REFUNDING me, booking.com debited my account AGAIN thus i was billed twice for a cancelled booking. They are taking no responsibility. The money never even reached the hotel's bank but booking.com declined my refund as they say the hotel must refund. The hotel didn't take my money!!! Booking.com did!