Who administers direct democracy mechanisms at the national level?

Electoral Commission Act (Act 51 of 1998)http://www.elections.org.za/content/WorkArea/DownloadAsset.aspx?id=987

1. (2) For the purposes of this Act, unless clearly inconsistent with the context, any reference therein to an election, shall be construed as to include a referendum declared by the President under section 2 (2).3. Establishment of Commission(1) There is an Electoral Commission for the Republic, which is independent and subject only to the Constitution and the law.(2) The Commission shall be impartial and shall exercise its powers and perform its functions without fear, favour or prejudice.5. Powers, duties and functions of Commission(1) The functions of the Commission include to?(a) manage any election;(b) ensure that any election is free and fair; [?]