Not paying for damages due to accident

My car was driven into by another driver from behind. What really protected my car mostly was my spare wheel in the back. I took my car for assessment, and the assessor saw and recognized the damages on the spare tire. He \apparently forgot\" to write it down and shortly after the assessment he left that company. My car went to the panel beaters and Absa idirect now refuse to pay for the tire as they say there are no damages. Yet they did replace the wheel cover as that was damaged from the impact. Now Absa idirect for you to make statement like that tell me did you come out to check? Absa idirect now demand i pay for it as they refuse to pay for it, yet i had been faithfully paying my installment monthly with them for over a year, and i had a contract with them, and they HAVE to COVER the costs. Worst Insurance company ever."