Do the people from Africa had any written native language ?

Question

I refer to central and south africa.

Answer 1

If by written you mean based on a local alphabet, I've heard of a local tribe in Cameroon (Bamun tribe, Central Africa), that had it's genealogy books written in it's own alphabet.
As for other languages, some of them have a precisely developed syntax and grammar most of the times like other languages (for the countries I know of, mainly dialects in central Africa) and some have a complete translation and dictionaries (If you try looking around you can find those).

Something else: due to Christian missionary involvement in the past centuries in Africa, bible translations exist in almost every native African Dialect, due to the fact, such translations were some of the first "jobs" of the first priests who settled in any place anywhere.
So if you're looking for a specific dialect translation or want to discover the complexity of some African Dialects, you can still ask your local Christian Catholic or Protestant church minister.
They could help (and I insist on the could).
But it'll still be hard to get a specific translation in a specific dialect, specially if it isn't widely spoken in a given country.

Answer 2

I'm from South Africa. Our "native language", both written and spoken, is Afrikaans.

Answer 3

I don't know but Afrikaans is not a native language.