Back billing demand raised citing recategorization of the consumer without following the due process of recategorization laid down in the GTCS -- Held invalid -- CGRF’s order without properly seeking the Hon’ble Commission’s clarifications where it was in doubt -- Set aside -- Classification of consumer categories -- Within the domain of the Hon’ble Commission -- DISCOM undertaking reclassification of consumers without there being any change in the tariff orders -- Held invalid.