Debi order must be canceled

I have paid off my account a few days before debit order date, I sent the proof of payment to one of the staff and asked them to settle my account and cancel debit order before it runs. Clearly it was not done, I have to debit order rejection on my account just because someone did not do their job. I need this fixed as I don't owe them anymore and why do they keep going to my bank account for something I have settled.