Hi Sophie
I only stumbled across your message today. Hope you have found a solution. Personally, I used Easy Equities. Work good for me.
I transfer straight from my foreign bank account into City Bank EE USD. Money reflects in a couple of hours ready for investing. Have done this for the last year and cannot complain. Once I have enough and feel limited to EE. You can transfer to Interactive Brokers like here,
https://investorchallenge.co.za/investing-properly-offshore-in-3-easy-steps/ Reason I do this:
*I prefer to have my currency in something stronger than RAND.
*I have a great fear in what happened to Venezuela
*I do not want to be limited to move money out of SA once I have permanently located somewhere else. (If all else fails and end up back in SA, you can still sell shares for monthly income and have proceeds paid into SA bank account)
Both me and my fiancé do the above and hope to achieve FIRE in a couple of years.

After being away from SA, I only now realize how volatile RAND is. I am lucky enough to have the benefit of receiving a foreign salary and spend it in local currency Zambia. Just cannot beat the benefit of buying goods which seems to be getting cheaper month to month. Groceries

But then again, I only shop for bargains.
All other things that are linked to the exchange rate, at least we keep up with the increasing prices.
Regards