Unjust enrichment governs excise refund claims when the amended refund law applies at the time of determination.

A refund claim under Notification No. 198/76-C.E. was governed by the law in force when the claim was actually determined, not by the law as it stood when the duty was paid. Because Section 11-B had been amended by then to incorporate the doctrine of unjust enrichment and bar refund where the duty burden had been passed on to buyers, the amended provision applied to the claim. The Court therefore upheld denial of cash refund and the direction to credit the amount to the relevant Fund, finding no infirmity in the order.

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Issues: Whether the doctrine of unjust enrichment applied to the appellants' refund claim arising from Notification No. 198/76-C.E., and whether refund could be denied once Section 11-B had been amended by the time the claim was considered.

Analysis: The refund claim related to clearances for earlier years, but the entitlement under the notification could be worked out only after the underlying dispute over the manner of calculation was resolved. By the time the refund claims were taken up, Section 11-B had already been amended to incorporate the doctrine of unjust enrichment and to bar refund where the duty burden had been passed on to purchasers. The Court held that the applicable law was the law in force when the refund claim was actually considered, and on that basis the amended provision governed the claim. The Court found no infirmity in the order denying cash refund and directing credit to the relevant Fund.

Conclusion: The doctrine of unjust enrichment applied, and the refund was rightly denied.

Ratio Decidendi: A refund claim must be decided under the law in force when the claim is actually determined, and where the amended excise refund provision incorporates unjust enrichment, refund is barred if the duty burden has been passed on.

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