Unfair Third Party dealings

Santam client skipped a 4-way-stop and crashed into me while riding my bicycle. I was thrown over the bonnet, smashed the windscreen, but fortunately only sustained minor injuries. Carbon bicycle broken in 6 places. Santam Third Party / Legal Department are completely ignoring the fact that their client jumped the stop street. and wants to assign contributory negligence, stating that I am 40% liable for the accident. I believe this is grossly unfair, but TP Legal are not prepared to provide reasons for their stance which is based on law / legal precedent. Very frustrating when you only receive standard copy/paste responses.