Free Cancellation - no refund yet

I specifically booked through Booking.com because of their free cancellation option. Well do not let that fool you. It has been 25 days since cancelling the booking within the allocated time allowed and after contacting the establishment was adviced to contact booking.com. No answer on any email address available and found a number to phone with much difficulty was told that tge refund takes 10-15 working days. After still not receiving the refund phoned again and was told a different story and that I need to complete a different form and then only wait 5 more working days. This is just unacceptable service. Will never use Booking.com again.