M.R. Shah, J.

1. Feeling aggrieved and dissatisfied with the impugned judgment and decree passed by the learned Judge, Commercial Court, Vadodara (hereinafter referred to as "learned Commercial Court") in Commercial Civil Suit No. 10/2016 by which the learned Commercial Court has partly decreed the said suit preferred by the respondent herein - original plaintiff (hereinafter referred to as "original plaintiff") and has held that the original plaintiff is for the recovery of a sum of Rs. 9,97,43,298.97 paise from the appellant herein - original defendant (hereinafter referred to as "original defendant") along with interest at the rate of 12% per annum from the date of filing of the suit till the date of decree and at the rate of 9% per annum from the date of decree till realization of the amount, the original defendant has preferred the present First Appeal.

2. Facts leading to the present First Appeal in nut-shell are as under:

2.1 That the original plaintiff - Oil & Natural Gas Corporation, Vadodara instituted Special Civil Suit No. 426/1993 initially before the learned Civil Court for the recovery of Rs. 9,97,43,298.97 paise with interest at the rate of 21% per annum from the date of filing of the suit till realization of the decreetal amount. That on establishment of the Commercial Court, Vadodara, the aforesaid Special Civil Suit No. 426/1993 came to be transferred to the Commercial Court, Vadodara which was numbered as Commercial Civil Suit No. 10/2016.

2.2 It was the case on behalf of the original plaintiff that the original defendant was in need of natural gas as fuel for its Unit at Naroda, Ahmedabad and therefore, the original plaintiff and the original defendant executed a Contract on 03.10.1985 at Vadodara for the period of 5 years i.e. commencing with effect from 01.06.1986 to 31.05.1991 containing the terms and conditions, definitions and interpretations therein. As per the said Agreement, the natural gas was to be supplied from the field of the original plaintiff to the Unit of original defendant at Naroda, Ahmedabad. That the defendant agreed to purchase 50,000 Standard M3 of gas per day and it was also agreed that if the original defendant purchase the gas less than 45,000 Standard M3 per day on any day, it shall have to pay to the original plaintiff for this minimum quantity. Thus, quantity of 45,000 M3 of gas was termed as minimum guaranteed off-take for the each day. The price of the gas was to be charged and payable as provided in Annexure-I to the Agreement and according to that the price of 1000 M3 of gas delivered at the Central Gas Metering Station, shall be Rs. 2878.87 paise inclusive of Royalty and exclusive of sales tax, duties, levies, cess, fees etc. as applicable and payable. It was also mentioned in the Annexure-I of the said Agreement that the price of the gas mentioned will automatically be adjusted and stand revised on pro-rata basis from the date of Ex Refinery price of furnace oil for non-fertilizer use charges which was considered as Rs. 2903.06 per Kilo Liter. It was also the case on behalf of the original plaintiff that as per Annexure-I of the said Agreement, the price agreed upon was subject to revision in accordance with the principles as may be laid down by the Hon'ble Supreme Court in Civil Appeal No. 8530/1983 filed by the ONGC against the Association of Natural Gas consuming industries of Gujarat. In the said appeal, the Hon'ble Supreme Court passed an interim order to recover price at Rs. 1000 per 1000 M3 for the gas supplied to those industries. It was the case on behalf of the original plaintiff that thereafter the issue of the price was decided by the MoP, NG and by its Notification dated 10.01.1987, the price of the gas was declared at Rs. 1400 per 1000 M3 of the gas at landfall Points and for onshore gas was fixed. That the said price was exclusive of Royalty, ta