Transitional Credit on non - moving inputs

You should defend the case by arguing that the reversal under the Excise regime was a temporary accounting adjustment for "non-moving" items, not a permanent forfeiture. Under the previous CENVAT Credit Rules (specifically Rule 3(5B)), such credit was reclaimable upon use. Since GST law does not mandate reversal for non-moving items, and the inputs were physically available for taxable supply, the transitional credit is a legitimate carry-forward of a vested right. Focus on proving the goods were never physically written off or destroyed.