Debit order nightmare!

I had purchased a vehicle in February, and Standard bank gave me the best rate. That is where the amazing service ended. Last month i was not debited and had to call in 5 days in a row in order for them to load a debit order for me. Again this month I am stuck with the same issue, I must call in to ensure they debit me in order for my credit record not to be affected. The agents are not helpful and management are always magically not available to ensure that the error is corrected. I don't understand how the process can have the same error 2 months in a row and why must i call to ensure that Standard Bank is doing what needs to be done.