System Error - double payment

Yesterday (28/12/2020) around 3pm, I tried booking a flight, whilst processing the payment on the site, it kicked me out and displayed a system error message; "an error occurred please try again". When I tried again, I was able to make the booking and the booking was successfully done. However, Mango deducted double - both flights (including the flight before displaying system error).

I went to the Mango guest service at the CPT Int. Airport, the consultant cancelled the first booking and asked that I call your refunds department today(29/12/2020). Now, I have been trying to get hold of the refunds department since 9am this morning to no avail. All I have been getting is; "Thank you for your patience - your call will be attended to shortly" - SINCE 9am and now it's after 11am...

The Tickets' reference are as follows: 1. TQQGHL (Which the consultant at the CPT Int. Airport Cancelled) 2. TQQGLZ

I am still holding on the line.