Claim amount not paid in full

I claimed for an incident, the insurer agreed for me to have the vehicle assessed and agreed to pay the claim. I had opted to look for a panel beater and Discovery paid (into my bank acc) the money they claimed was enough to cover the costs. I then complained to Discovery that the money they paid was inadequate as no panel beater was willing to fix the vehicle for that amount. An agreement was reached that I take the vehicle to Riverside Auto body and that if there is any shortfall, the insurer will pay for it. However, after the vehicle was fixed and the panel beater informed me to fetch my vehicle, the insurer had not paid the shortfall amount and since I was in a hurry I paid for it with an understanding that I will be refunded the money. Almost 2 weeks after I fetched the car, numerous emails exchanged and phone calls, Discovery has not indicated when they will pay me my money nor paid any money.