Advice needed

I need some advice. I ride a motorbike. Last week, on my way home, this guy jumps the stop almost causing a collision with me. I had to take evasive manoeuvres to prevent an accident. So, naturally I flip the guy the bird. He did not like that at all! He turns around, drives up fast behind me. I am thinking the guy is going to rear end me, so I pull forward next to the car that was in front of me to block him from rearing me. I was trapped at a red light. He gets out of his car, walks up to me in a huff. I say that he could’ve seriously injured me. Walks right up to me and hits me in the face. I have an open face helmet. Had a bit of blood on the inside of my mouth. Upset, I try to remember the plate, but was only able to memorise the first half of the plate and description of the car.

Anyway, few days later I think to myself, fuck this guy. Called the neighbourhood watch, explained what happened. Initially they could not locate the car and eventually someone calls me and confirms the car matching my description at the time of the incident. He even sent me a picture of the car with its REG number taken out. The guy tells me I am not allowed to have this info, nor share this knowledge with the SAPS (since it can damage my case) but they can hand it over to SAPS.

Go to SAPS, lodge a case. SAPS calls me the following day saying he is with the neighbourhood watch, but there is no car matching the description. I can only assume that they looked at the wrong cameras like they did initially. I call the neighbourhood watch asking why they did not provide footage of the car and the response was that the guy who talked to me knows about the case but he is on leave until Friday. Today I receive an SMS saying the case is closed. Like WTF.

What can I do now?