Standard Bank VAF- debit order

Signed a Vehicle agreement with the bank and the debit order date in the contract was 1st of each month and even received a debit check to authorise on the App. On the 1st, the bank failed to debit and I made thousands of calls trying to enquire if I should make a manual payment and also the date. I was informed that the date loaded on the system is the 28th of March which is shocking because i did not receive any debicheck nor did my contract contain such a date. I requested that everything be as per the contract and they sent a revised plan with an amount more than the initial amount on the contract. This amount is more than the initial cost of credit because there are interests added. So now I got a debicheck to authorised payment of the new installment which i queried for almost 11 days now with no progress. One person will tell you to do manual payment but can't confirm if you paying on the revised cost of credit or not. No one can give answeres as to why the bank did not debit, why the person loaded a different date than what is in the agreement? Why was I not informed as a party to the agreement? I just do not understand how a bank can changes to a material term of a contract without informing the other party. My question is had I not called and queried, how would I know that the date loaded is incorrect and how would the debit order go through without my authorization on the App??? I am soo disappointed in standard bank and how they handle their affairs. Now I have to pay for interest when the bank failed to debit and loaded a different date? Its been days of calls and everyone is telling me that they will talk to their supervisor and it ends there. The next debit order date is coming soon, what do I do???