‘The personal data of millions of South Africans, "stolen" in one of SA's biggest data breaches earlier this year, has been discovered on the internet, despite

‘The personal data of millions of South Africans, "stolen" in one of SA's biggest data breaches earlier this year, has been discovered on the internet, despite assurances that the information had been recovered.’ Technically speaking, how do you go about recovering data stored on any amount of copies?