FNB Brokers

Our business has recently made a motor vehicle claim via FNB brokers and was not happy with the assistance their broker. They approved part of the claim and when I inquired why they have not approved everything from the report of the assessor, I was then informed that I need to put a separate claim for the rest of the damages and should note that we would need to pay another excess for that claim. How does a broker say we need to pay 2 excesses for the same claim? Can someone at FNB brokers explain this to me please!