Green’s Dictionary of Slang

(S.Afr. Und.) prison.

2005		A. Lovejoy Acid Alex xix: I can’t end up in a French mang because I have [...] no drugs in my possession.
2008		A. Lovejoy ‘The Smell of Tears’ at www.acidalex.com 🌐 2: Inside the mang he used to be a makwera in the land of nchonalanga. A prison fighting general.