How do I rectify outstanding RA amounts, without the documentation?

SARS says there is an outstanding amount from a RA in a 2012 Tax Return, because of this I have a very high penalty to pay. I can not find this documentation, even after I've requested it from my RA at the time. What do I do if the numbers don't add up, and I can't find this document.

You would need to go to the police station and swear and affidavit stating the situation that you could not get the certificate and submit that to SARS.