Interest still charged when balance was settled in full

On 4th May 2026, FNB credit card charged my account with R874 of interest. On enquiry, I was advised that this was because a debit order failed on 25th April. However, I settled the full balance on the credit card account by 30 April and thus no interest should have been charged, regardless of whether the debit order failed or not. FNB was paid in full by 30th April. This seems like another banking trick to separate you and your money.