STANDARD BANK'S SYSTEM WILL LET YOU DOWN!

I recently wrote to Standard Bank Home loans to update my debit order date and banking details . My debit order had always been going off on the 20th of every month . My account has never been in arrears or late . I received notification that my request to change my debit order to the 25th had been actioned and that my next payment date would be 25/05/2019 as the debit order for 20/04/2019 had already gone off . HOWEVER IMMDEDIATELY AFTER THAT I STARTED RECEIVING MESSAGES FROM STANDARD BANK HOMELOANS THAT MY ACCOUNT WAS IN ARREARS AND THAT I NEEDED TO MAKE A PAYMENT BY 01/05/2019 . I THEN CALLED IN ON 26/04/2019 ONLY TO FIND OUT THAT WHEN THE DEBIT ORDER DATE WAS CHANGED THE SYSTEM PUT MY INTO ARREARS AND DEMANDED ANOTHER INSTALMENT EVEN THOUGH A PAYMENT WAS MADE ON 20/04/2019 . HOWEVER I WAS ADVISED THAT THIS WOULD BE RECTIFIED ! BUT I AM STILL GETTING CALLS THAT MY ACCOUNT IS IN AREARS AND THAT I MUST MAKE A PAYMENT OF R11599.00 BY 01/05/2019 . WHO WILL PAY FOR ALL THESE CALLS ? AND THE CHARGES AND INTEREST ON MY ACCOUNT AS CLEARLY IT IS THE BANK'S SYSTEM THAT HAS FAILED ME !!