Nedbank insurance claim frustration

On 13 Feb in Bloemfontein our whole premises were flooded after heavy rain. We reported the claim but after 2 months we received no communication and i folliwed up - only to hear that our claim have been rejected due to "damage caused over a period of time & gradual deterioration ". It has been another month afer i submiited a complaint. To call the call centre is very frustrating and unsucsessfu so i send 3 emails during the passed month without any reaction as well.