Capitec with holding refunds from being cleared into my account

Booking.com did a refund into my Capitec account, for a booking cancelled on the 10 August 2025. Booking.com recently informed me that they processed the refund on the 11 August 2025! It's been a while and the money is not released into my account yet. The refund apparently says 'Pending'. Called Capitec, Capitec is asking for an Authorization Letter, before they release the refund from Booking.com into my account. Why do I need this letter, to get my own money cleared back into my account? I desperately need this money and am out of pocket because of Capitec. I want my money to be released/cleared into my account. When is this going to happen, and what happens if booking.com doesn't provide the authorization letter? This refund issue only seems to be with Capitec.