Refund Policy - wait forever

I was trying to book tickets from Lanseria to Durban for my partner and I. This was for the 13th of October. Due to system errors, my card was charged twice. So I was booked for four tickets on the same flight for two people, and also I did not receive any email reference for any of the bookings. When I had called the mango call centre, I was advised that they did experience technical difficulties on the day, they sent me a reference for one the bookings. But I had to call back to request a refund as they could not process at the time. Which I did do, and was told, mango needed to investigate and then will get back to me, after knowing there was a system error. I was told after I contacted them three or four times, that the double booking will be refunded. However, it takes 10-14 working days. It's now 31st of October, and I'm still awaiting my refund. When I advised the person I spoke to last, why don't you tell customers, refunds will only be done after fourteen working days, not 10-14 as they said previously, he said no, it takes anywhere in between 10-14. It's strange, cause when you book a ticket, an opt to pay later, you have 48hours to do so. Or if you book online, payment must be done immediately. So on the call today, I was told, the refund is sitting with finance department. Maybe processed today it tomorrow, who knows.