Flight Instructor Ratings will not convert, but if you hold an instructor rating from a contracting state - not sure if SA counts - some of the ground school hour requirement may be waived. Keep in mind you still will need to convert your license to a TC CPL or ATPL to have a license on which to attach the rating.
More info here (see section 7 for Credits for Foreign Applicants):
Part IV - Personnel Licensing and Training - Transport Canada