Standard Bank Home Loans No accountability

My home loan payment is on debit order with Standard Bank Home Loans. The debit order did not go through on the date specified. The next day I received a sms stating that my account is overdue. I immediately called the Home Loans division and was told that "our system is faulty". I was asked to do and EFT, which I immediately did. Please keep in mind I pay more than my actually repayments every month. Yesterday I get another call from Standard Bank, telling me I have not paid. So again I send my proof of payment to the consultant. She called me back to let me know that everything is now sorted. I swapped a digit around on my reference number when I paid. I humbly apologised and thanked the consultant. A few hours later I receive another sms"You have not honoured the payment arrangement on your home loan account.....to avoid escalation to our attorneys call ***" I held for over 20 minutes trying to get through to them and eventually hung up. Their system is faulty but they accuse customers of no or late payment!! I am very disappointed to say the least.