Yes indeed South Africa was wrong in this way for Daylight Saving Time but will you able to fix the Daylight Saving Time for South Africa?
Are you able to clarify further how you feel our data for South Africa may be wrong (for which years, for which dates, etc.) and, again, provide some reputable sources supporting that claim? Absent that, given the high confidence we have in this case in our existing data, it would at the very least be extremely helpful to have specific examples of how our data handles specific conversions in ways that differ from what you expect, e.g.:
A better understanding of what specifically you think is wrong will help us determine whether the supposed error is in our data or somewhere in how you or your toolchain may be interpreting it.