Unauthorized debits again on my bank account!

Once again FNB has debited my account with R378.00 for an unauthorized debit for Just Answer Veternary Services. I still have a debit for this amount from this company on my account from November. Who authorized this amount and 2 months in a row now. ? Not me !! The service is disgusting. Only solution seems to be to close the account. They will not even comply as there is now a debit on the account.