Your views are full of logical force but devoid of statutory force. Govt. has no right to be enriched unjustifiably. The department is allowing interest on the amount of pre-deposit within three months from the date of decision of Appellate Order which was as per Central Excise law. Trade should have raised their voice earlier as opined by you.The voice should have been raised when the pre-deposit amount was raised to 7.5% & 10%. It is pertinent to go through the following case law:-
Refund of pre-deposit - Interest on refund whether payable from date when appeal allowed?
The Supreme Court Bench comprising Hon’ble Mr. Justice S.A. Bobde and Hon’ble Mr. Justice Navin Sinha on 10-12-2018 issued notice in the Petition for Special Leave to Appeal (C) No. 31522 of 2018 = 2018 (12) TMI 592 - SC ORDER filed by Commissioner of Trade and Taxes against the Judgment and Order dated 10-8-2018 of Delhi High Court in Writ Petition (C) No. 3118 of 2018 as reported in 2018 (19) G.S.T.L. 478 (Del.) = = 2018 (8) TMI 995 - DELHI HIGH COURT (MRF Limited v. Commissioner of Trade and Taxes). While issuing the notice, the Supreme Court passed the following order :
“Issue notice.
Until further orders, the operation of the impugned judgment and order passed by the High Court shall remain stayed.”
The Delhi High Court in its impugned order had held that since refund of pre-deposit became due and payable from the date when appeal was allowed, assessee was also entitled to interest calculable from the date such appeal was allowed.
[Commissioner of Trade and Taxes v. MRF Limited - 2019 (20) G.S.T.L. J47 (S.C.)] = 2018 (12) TMI 592 - SC ORDER
Also see the extract of Board's FAQs in this context which is relevant to the GST regime.
FAQ dated 31.3.17 (Second Edition)
Q18. Whether interest becomes payable on refund of pre-deposit amount?
Ans. Yes. As per Section 115 of the Act, where an amount deposited by the appellant under sub-section (6) of section 107 or under sub-section (8) of section 112 is required to be refunded consequent to any order of the Appellate Authority or of the Appellate Tribunal, as the case may be, interest at the rate specified under section 56 shall be payable in respect of such refund from the date of payment of the amount till the date of refund of such amount.