Unjust enrichment determinations require detailed financial review to decide refundability and whether duty burden was passed on. Unjust enrichment requires the Assistant/Deputy Commissioner of Customs to examine audited balance sheets, financial records and Chartered Accountant certificates to determine whether an applicant passed the incidence of duty or interest to another person; refund orders must be speaking orders identifying specific records and reasoning, and routine credits to the Consumer Welfare Fund without case-specific analysis are insufficient.