Amending your tax return after submission

I'm a first time tax payer. I only completed my tax return for the first time this year. I used e-Filing and already submitted my tax return, and received the assessment. I realised that I had to add my Medical Aid tax certificate (My company is not paying for my medical aid, it comes from my pocket). What should I do now, seeing that I already filed my tax return? How am I going to fix this?

You need to go back to SARS eFiling and click REQUEST CORRECTION under the tax return and then you can refile with the corrected information.