we are are civil contractor company, we had made a JV to carry out the Parking work of a State, the Work was issued by the Local Authority of the state and non commercial work as the work was to avoid congestion of traffic. as we had just made JV for this project and as per notification 25/2012 , the same work was exempted hence we had not registered ourself in service tax & we had not levied ST to Client in our Invoices and not they had given also . now we had received a SCN stating that we had to pay ST on the same work, however we had informed regarding the exemption but the officer is not ready to listen, and he his also saying that we had to get registered to service tax?