Refund not paid after 31 working days

I had to cancel bookings for 3 passengers, the cancellation was done on the 12th of December 2023 and was told that the refund will reflect within 15 working days and till this days I haven’t received my refund and every time I call or send a WhatsApp regarding my refund I keep getting the same reply that my refund is with the finance department today marks 31 working days and I have still not yet received my refund. I want my refund.