9. Per contra, Mr. S.C. Keyal, learned standing counsel, Central Goods & Service Tax appearing for the respondents has vehemently opposed the writ petitions and has argued that the learned Single Judge has not committed any illegality in dismissing the writ petitions filed by the appellant Company on the ground of availability of alternate remedy. It is contended that the appellant Company has essentially filed the writ petitions being aggrieved with the decision of the Assistant Commissioner, GST & Central Excise, Guwahati, whereby the claims of the appellant Company for refund of taxes has been rejected. It is argued that under the CGST Act, 2017, complete mechanism is provided for redressal of the grievances of a person aggrieved by the action of the authorities and in such circumstances, the writ petitions filed by the appellant Company are not liable to be entertained.