Where an amount required to be refunded by the Commissioner to any employer or person by virtue of an order issued under this Act is not so refunded to him within ninety days from the date of the order, the State Government shall, pay such employer or person a simple interest at the rate of six per cent. per annum on the said amount from the date immediately following the expiry of the period of ninety days from the date of such order:
Provided that, where the amount becomes refundable by virtue of an order of the Tribunal, the interest under the provisions of this section shall be payable from the date immediately following the expiry of the period of ninety days from the date of receipt of the order of the Tribunal by the officer whose order forms the subject of the appeal or revision proceedings before the Tribunal.]