Almost a month still haven't received my refund

On the 20/11/24 I purchased 3 return tickets from Midrand -Queenstown 14/12/24 and Queenstown -Midrand 21/12/24 however due to unforeseen circumstances I had to cancel the tickets which I did on the 08/12/24 According to the condition of carriage, the policy clearly states that; tickets that are cancelled shall be refunded into a bank account within 15 working days. However is very disheartening that even today I haven't received my refund after numerous attempts to contact them on their WhatsApp page my issue is not resolved