I guess, you could try this. But if they have a list of online sites, where your credit card can not be used, then I guess, they could also have a list of the bank accounts used by these companies and decline any request for a SWIFT transfer to these accounts. I would also guess, that if SAs government has this policy against e-Vallets, then perhaps this also include crypto exchanges? And probably not only to prevent online gambling but also moving money around outside the official banking system in general?
Its almost to the point, where your best option might be to enlist the help of someone outside SA, send them cash with a service like MoneyGram, Western Union etc. and have them make the deposit for you. But if its that complicated, I might personally just give it up to be honest with you. As you say, there is also the issue, how you are going to get money out again, should you win anything. So whatever you do, I would definitely advice you to not deposit more, than you can lose without feeling devastated about it.