Capitec breaching contract

Capitec is breaching contract on a loan I made with them by deducting money from my account before the agreed payment date when I receive my salary....every month I have to pay the debit orders that fail .. This month they deduct again but there was enough money in my account on the 22nd instead of 28th now I have to pay for the reversal of this said money, and I have been paying each month for the failing debit orders. Now I have to pay R500.00 for the reversal of their mistake again