That is not true. When the Dutch first arrived in SA, they found the place depopulated. People are often surprised to learn that, prior to the Nineteenth Century, the whole black population of Africa was restricted to a narrow band about the equator. The Dutch WERE the first large migration to the region. The Zulus didn't reach south until well after white settlement.
Cape Town, yes which is just off the Cape of Good Hope. There were nobody there except for nomadic tribes such as the Khosian. Bantu tribes had already settled in the northern part of South Africa before the Dutch arrived.