Please refund my money

Around August my husband and I missed a flight and Mango Airlines promised us the next available flight. We paid using a card but when we were told about the time arriving at OR we realised we would miss our next flight. We informed the manger and she understood gave us a ref number and told us our money will be refunded to us after 5 working days. Now its December there is still nothing. I've been calling the call centre they keep telling me, I cant get a refund. How is that so? I want my money back because I practicality paid for nothing. Why would I just give money away? Why was I told I would get the money and why am I not getting my money back for a flight that I didn't use. This is unacceptable.<br> <br> <br>