Claim rejected for Wear and Tear / Settlement

I submitted a claim in October 2019 - my entire house (16+ years old) has developed cracks on the main building and the new extension (5+years old). A year ago we had major floods (I notified Outsurance of this at the time and nothing was done!) - if you live in Durban, you'll remember how heavy the rains were. This has caused major settlement on the entire structure and Outsurance has rejected my claim due to Wear and Tear and Settlement: Their response: "Damage caused by the downward movement of land resulting from natural shifts or human activity, causing structural damage to your property. There is no cover for damage relating to subsidence caused by:-settlement, shrinkage or expansion of the soil supporting the structures." My house was built to NHBRC standards and after 11 years as a customer, I have no claim for these “events” (which only occurred in the past year – no issues with the building before that) that have arisen from no fault of my own. Outsurance went further to send out Detect-A-Leak and a structural engineer they found no issues with the pipework. My house is sliding and have just received a quote of R 450 000 to fix this “wear and tear” damage which I cannot afford right now. There’s cracks on walls, inside and outside almost everywhere. Ceilings being pulled apart. Paint bubbling. Floor slabs breaking away. I don't understand how Outsurance can expect that this is a natural shift, given scale of the resultant damage. They want a single Event that caused this, but these types of events take months to reveal themselves. When Outsurance insured my property all those years ago, did they come over to my house and assess the risks or advise me on these possible events that could lead to such a huge claim? Or how to prepare / remedy / maintain? NO. I guess I have to wait for a catastrophic event such that my house washes away to validate a claim.