MiWay's disappointing service

We got into an accident in 2020 and lodged a claim with MiWay. MiWay agreed that they would pay me R20 000 for my vehicle to get fixed. They then said the person who had bumped into my vehicle would have to pay for the damages and not them. MiWay only paid me R4000 and told me that they guy who bumped my car only gave them R4000. Everytime we call them to ask when we will get the rest of the money, they keep telling us that they cannot reach the guy. We have been struggling with this matter since 2020, it still has not been resolved till today.