Change of Status from ZSP to main stream Visa in South Africa

DHA allowed ZSP holders to change status of Permit to main Stream Visas, but when I did an application. I was shocked that I was rejected and the reason being I am not allowed to change status of my Permit in the republic. And that's the only reason stated on the rejection. It is unfair. http://www.dha.gov.za/index.php/statements-speeches/1034-statement-by-minister-mkhize-on-the-closure-of-the-zimbabwean-special-permit-zsp-and-the-opening-of-the-new-zimbabwean-exemption-permit-zep