Charged R4000 insteaf of R4 in R1 special

Making a booking for 2 return tickets from Joburg to Cape Town, I was charged R4000 instead of R4 when paying on my iPad. I definitely selected R1 tickets, and confirmed this afterwards by checking the dates and times (R1 tickets were still available for these dates and times after I booked, and regular price tickets would have totalled R1996). Definitely deselected all extras (this is also shown in my booking confirmation). The price shows as R4000 minus a R3996 discount, but when the payment eventually went though (after a few tries due to the strain on the website) I was charged R4000. My posts on facebook and twitter are just getting buried under everyone else's complaints about the website. I can't contact them through the website or the call centre because everyone in the country is using them at the same time. Please refund me the R3996 that I have been overcharged.