I know that the United States Antarctic Program has at least four helicopters based at McMurdo Station, which are used for flying personnel to field sites that are within helicopter range. There are no helicopters at South Pole Station. I can't speak for other stations or other nations.
However, some cruise ships may also have helicopters, so that might be your best chance. Alternately, if you can fly small fixed-wing aircraft you might see about getting a job with Kenn Borek, which is based out of Calgary, Alberta (Canada) but does a lot of flying in both the Arctic and the Antarctic.
With your nationality, you might have a chance with the South African, British, Australian, or New Zealand programs (except I don't think New Zealand is using any helicopters in Antarctica). There's even a slim possibility of getting hired by the U.S. program, but I wouldn't count on it.
In the meantime, Cape Town is a nice place and you even have penguins, so take the time to appreciate what you have. ;-)
Best of luck.