For Direct Debits, your Import Type Template (1) File type selected on the first step must start with "Direct Debit - ".
The Direct Debit mapping is not delivered with the product by default. You will need to set this up on the first import by saving the Import File Template on Step 2 as Direct Debit.
Note: If your import file is for initial loads only and you do not wish to create Opportunities, then select "Contact Load Only" checkbox on the first step of the import wizard.
Make sure you map the Account No. and BSB fields as part of the import
Please note the BSB need to be in "XXX-XXX" format.