they dont want to reverse

hi on 3 July 2015 SARS deposited money into my account and my bond was deducted for R4000,i went to the dobsonville branch Malibongwe told me they cant reverse it Absa Home Loan should reverse it.Called them they said they cant I have to speak to Thomas as he is handling my account.Thomas told me i did a direct debit to the account why would i do that as i need the money for my son 2nd Simester registration.To date i have been taken from pillar to post and the closing date is on the 18 July 15,who gave them authority to debit my account as it was paid on the 25th June as per our agreement.Someone has to be liable for this as i stopped the debit order and it still goes through on the 20th and that causes services charges for always.