I was born in Wes Germany but have a South African passport - my parents are also South African, do I qualify for a German passport

How long did your parents live in Germany at the time of your birth? Did they continue to live in Germany afterwards? Did they register your birth with a South African Embassy or consulate as a citizen born abroad? Have you lived in Germany for any extended period?

Unlike the US, being born in Germany does not give you any citizenship rights it is the citizenship of your family.
Do your parents. If you were born after 2000 ( which I assume is not the case) then if your parents had been living in the country for over 8 years or was legal resident of Germany, you may have citizenship rights under their newer laws.