Daylight ******* by Discovery insurance

My insured vehicle caught on fire whist driving, I am still under the impression that the lightning was the root cause of the fire as I heard a loud sound. Discovery insurance rejected the claim on the following grounds. 1. Discovery appointed Danati fire investigations to investigate the loss, its findings were as follows. 2. There are no signs of any foreign object such as a vape or charging bank that may have failed and started a fire. 3. The confident conclusion of this investigations is that this was an intentionally set fire. My desire is simply to get fairness and I requested the insurance to prove an individual caused a fire deliberately as I will not rest until I am convinced but to no avail. There was very slight rain that could be possible that the vehicle struck by the lightning and destroyed inside of the vehicle as we all know that lightning is a natural disaster and can ignite a fire potentially destroying the vehicle however Discovery doesn't consider the lightning as I have explained to them during the claim process. Discovery insurance rejected the claim based on their experts report, as things stand I really need the fire investigator to prove an individual caused a fire deliberately.