Iwyze claim

I took an insurance with old Mutual iwyze and was involved in a car accident that resulted to my car been written off. The third party was responsible for the accident and owned up to it we verbally agreed that he is gonna be liable for any outstanding payment if the insurance doesn't fully payout. The insurance paid out the value of the car to my car finance and I had a shortfall of R68 000, I received a letter from iwyze that my policy had been cancelled after paid. They told me that iwyze has done their part, so I spoke to the third party about the credit shortfall I was surprised when he told me that he has made an arrangement to pay iwyze 1000 a month on my claim, I called iwyze to enquire and was told that he is paying the R193 000 that iwyze paid to my claim. They excluded the shortfall of 68 000 and told me that if I take the third party to court I would be committing *****. What I don't get is iwyze is claiming from the third party because they know that he was the cause of the accident and it was a loss to them but I cannot claim from him though I have to pay the 68 000 shortfall for the accident I didn't cause. My car was insured and I never skipped any premium so y are they claiming from the 3rd party and I have to see to it that I pay the 68 000?