MYOB Online Backups - Clarification Required: Duration & Retention of Backups

MYOB is still missing the point, reports do not give us access to the actual document stored in MYOB & attached to the tx.  As required by ATO we must produce the actual receipt, tax invoice, subbie statement etc, etc, if requested.  For years we have been encouraged to store these in the software and go 'paperless', if we cannot access our closed file or back up of the closed file prior to closing, then we have lost all these scanned receipts, invoices, pmts etc.  And that is not acceptable or available via a report!!!!!!!!!!!!