Double charge because of *********** call centre staff

Changed my flight booking which incurred an additional charge of nearly R3 000. Payment went through on my bank account but not on the FlySafair site. Needed to resolve this issue so I phoned the call centre and was told that the payment hadn’t gone through (even though my bank said it had), and I had to reprocess the payment, which I did. Guess what – both payments processed – FlySafair admit it was their error, but I mustn’t worry, they will process a refund which can take up to 21 days- they are incapable of / don’t want to deal with this refund urgently even though they admit they were at fault. This is great for their cash flow but not so great for mine! Absolutely appalling service, if you are responsible for the error, you should take responsibility for fixing it with some sense of urgency.