Standard Bank look at my flood damage during the floods KZN areas where declared a state of disaster

My Policy number with Standard Bank:HLB*** Claim number22/128842 During the floods in KZN this year my home in Margate received serious damage A wall of mud and water came down next to my house and crashed into the rear wall of my garage,and during the period the rain just carried on eroding my ground,I have 2 supporting retainer walls that didnt collapse but started to lean over.my claim has been refused by Standard Bank insurance twice now,I just cannot get them to understand my supporting walls didnt collapse,and the damage was from flood water coming through the property,below is there last answer to me. why have they done this to me we had a state of disaster The structural damage on the retaining wall structure were due to defective engineering designs and construction methods that were adopted during initial project development. The retaining wall structures was not provided with adequate subsurface and surface drainage system which has negatively impacted on the structural integrity: hence it has failed under load. Inadequate back fill soil material were used to fill the build the platform terrace: it was further found that the back fill soil material were not adequately compacted hence it has failed under the load. The structural damage observed on site were not due to immediate event or unforeseen circumstances but had occurred overtime or gradually. Unfortunately this type of damage is not covered in terms of the policy. Attached find the policy wording for perusal.