Bad service

Hi,I’d like to lodge a formal complain against Diepkloof Zone1 police station. My sister was beaten by a guy he got arrested and released within an hour,on what grounds we don’t know. I have heard a lot of stories about Diepkloof Zone1 police station people saying it’s pointless to open a case there cause they get bribe and the person will definitely get away with anything. So is this how the justice is served? Is this why they hired them? Is this why they are being paid for ? With our tax money? To be specific the detective is Randy Malatji this is not the 1st incident I heard about him taking bribe