Cancellation options and refund

I attempted to make a booking for a 3-day stay in Centurion via Booking.com. While processing the payment, I changed my mind and did not confirm the payment through my Discovery app. However, when I checked today, I noticed that the payment had still gone through, despite me not approving it.

I contacted the property to request a refund, as I will no longer be travelling, but I have been unable to cancel the booking through the app there is no cancellation option available. Additionally, their customer service number is not going through. I am requesting a full refund, as I do not understand how the payment could be processed without my approval.