21 Working days for a Refund that is the Airlines fault

Due to a website glitch, I was billed for tickets even though online it said there was an error and I must start the process again. I went through the process again and ended up with two sets of tickets, and was charged for both.

After dealing with customer service, I am going to be refunded, but ove been told it takes them 7-21 working days for them to pay me back money they owe me due to thier own fault? I need that money to pay for things, it is R24,000 that they are just going to sit on for up to 21 working days.