Commission under its order dated 15th September, 2007 has made substantial changes in the open access agreement executed between the parties and Clause 29(1)(f), in particular, which was clear in terms that during the period of outage of the generating unit effecting the open access supply because of which all inadvertent supply would be charged as per temporary supply tariff which has been substantially altered by the Commission and instead of the tariff for temporary supply, the tariff for regular supply became payable for inadvertent drawal and this cannot be considered to be a mere clarification under the terms of agreement executed between the parties and if that being so, all such substantial modifications/amendments which are made under the terms of agreement, in no manner, can be read prejudicial to the interest of the parties and if such substantial change which has been given effect to is given retrospective effect, that indeed will seriously prejudice the rights of the respondents, more so, when the conditions of the open access agreement with which the present dispute is concerned in reference to Clauses 29(1)(e) and 29(1)(f) of the agreement are neither in contradistinction nor in contravention to