Warranty claim at king price

Beverley de wet from king price warranty claims have advice me to send necessary documents regarding my claim. Including service book of my car, later she said she don't need service book but invoice, I sent her invoice. She also request the same to mechanic, then she said said the car was not serviced as per manufacturer intervals, then I I explain to her that MG6 are being serviced at 15 miles which is 24.1kms when you convert miles to Kms in South Africa. Manufacturers service book for UK is 15miles.she still denied that the car was supposed to be serviced at 15.000 Kms all MG6 are serviced at 24000 Kms. Then finally she declined the claimed with the reasons that the water bottle that burst was the course of the car to overheat and blown the engine. Water bottle that burst is the part of the cooling system. As per policy the car is covered for overheating. King price is looking for any minor thing to avoid the claim