Extend Tourist Visa (Cape Town)

I arrived in South Africa a few days ago and am applying to extend my tourist visa for an additional 2 months. I did the application online and got an appointment. The checklist they sent me is for a Visa Application and includes medical report, TB report, and police report. Are these really necessary to just extend an existing Visa? I have emailed them to ask, but don't know if I will get a reply. I am in Cape Town. Thanks.