Helpless regarding insurance

My dad is 87 years old and has been with STD Bank insurance for a lifetime because he was staff and is now a pensioner. He pays more than R2500 every month for household and car insurance. He cannot pay it on his own. I pay half for him. My frustration is that any big claim they reject and we land up having to sc**** the Hundreds of thousands to pay for any repairing. We researched builders, examined their work and built on an extension. 7 years later cracks started appearing after the heavy rains and the builder was nowhere to be found. We sent in a claim and it was rejected as shoddy workmanship even though we had followed all the correct paths, professionals and inspections. We had to pay out of our own pocket to have the house underpinned in 3 places and the building repaired. All our savings were used and I had to help my dad out. We did go to the ombudsman and he sided with the insurance. 3 years ago some cracks appeared and we repaired them. End of last year, there was heavy rain and some of the sand under the cement had washed away. Again the insurance rejected the claim. I paid out R60000 to have them dig up , reinforce and concrete everything and put in new channels to help force the water away from the house. Now the cracks have started again. No surprise,the insurance has rejected it. I seriously do not understand what we pay so much money for when they only pay out for small claims and one has to wonder where we are going to find the money to solve this problem. We are both pensioners and my savings was used earlier. I am also concerned about whether they would pay out if our house was washed away in floods as Amanzimtoti has heavy rains. I am feeling very helpless and have no way to comfort my dad who really thought they would pay out. WHY DO WE PAY INSURANCE. All insurance do exactly the same thing but perhaps they would be cheaper