Confused

I got my provident fund from Sygnia now in January and I was shocked to learn or to be informed that SARS had taken a huge chunk of that money, my payout amounted to R10800 and I only received R3800 and was told SARS had taken 70% I am stil puzzled as to why that is. When I was working I did not fall within the bracket range so now how come they get to take such a huge percentage? Please help me to understand what really happend.