Regent doesn't honour third party claims

One of our vehicles was involved in a third party claim against a Regent client. Regent have only agreed to pay R6107-13 for repairs that have cost R15000. When asked how they expected the panel beater to repair the vehicle for R6107.13 they didn't bother to respond. We have since fixed this vehicle ourselves for R15000 but we want Regent to honour this third party claim which they have already acknowledged that they are liable for by insulting us with an offer of R6107.13. Regent are sharks who hope to pay out as little as possible while hiding behind their lawyers. I even cancelled 4 of my own top up policies with Regent as their work ethic is shocking.