Unhappy customer

I have an account with FNB so I also took a short term insurance with them I missed 1 payment due to the looting so when I had a claim I was told about this payment so I told them it's OK to take the money as long as my policy was still active but instead they declined my claim canceled my policy and still double debited my account now they don't want to pay me back if a well known bank like FNB can ***** from their clients who can we trust