Miway refuse to pay 100% claim for damages on my car caused by their client

On the 30th of Nivemeber 2019, I was involved in a car accident with a miway client, I was on the N3 south gauteng, exactly on the N3 and N12 slip, I was on the far right lane of N3 as I was driving to Katlehong or Spruit direction ,suddenly I heard a noise on my left side,then I reduced speed, then I saw car rolling just in seconds,only find that the driver tried to overtake to my lane, I stopped immediately ,then the miway client admitted that he is the who is wrong, then the guy logged a claim, and I am the third party, I submitted all the documents, then now miway are saying I contributed to the accident with 40%,therefore they will only pay 60% of the quote I submitted to them. I have asked them if they know what speed their client was travelling at and also on what speed I was travelling with, and because the accident happend on the N3 and N12 split, what if their client wanted to take N12 and it was too late for him to take N12 that's why he caused the accident , their client is 100% wrong, they suppose to cover all the costs....it is just clear that they didn't even read my sketch and summary of the accident,because they state very well that according to their clients info I was wrong as well, they dont say anything about my statement.

The miway team are ****** and ***********.