Refund cannot reopen a final self-assessment where valuation was never challenged and assessment remains binding.

Refund proceedings cannot be used to reopen an assessment or valuation that has attained finality. Where duty was self-assessed under the RT-12 procedure and no appeal was filed against the completed assessment, the assessable value and duty determination remained binding. A refund claim based on credit notes for after-sales service, because it effectively sought alteration of valuation, was not maintainable without first obtaining modification of the assessment through appeal or review. The refund claims were therefore rejected, with the assessee's appeals failing and the Revenue's appeals succeeding.

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Issues: Whether refund claims seeking deduction from assessable value were maintainable when the assessment and valuation adopted in the RT-12 returns were not challenged in appeal.

Analysis: Refund proceedings cannot be used to reopen an assessment or valuation that has attained finality. Where the assessee self-assessed duty under the relevant procedure and no appeal was filed against the assessment completed on the RT-12 returns, the assessable value and duty determination remain binding. A claim for refund based on subsequent credit notes towards after-sales service directly affects valuation and, without first securing modification of the assessment, cannot be entertained. The issue squarely falls within the rule that refund is not an appellate or review mechanism against a completed assessment.

Conclusion: The refund claims were not maintainable and were rightly rejected; the assessee's appeals fail and the Revenue's appeals succeed.

Ratio Decidendi: A refund claim that in substance seeks alteration of an unchallenged assessment or valuation is not maintainable unless the assessment has first been modified in appeal or review.

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