We are manufacturer of conveyors, we will manufacture goods in semi finished condition and clear under central excise duty payment to our customer place. At our customer site we will erect / assemble the all parts and trail the equipments and we will commission the entire plant. At our customer site all the activities done by our sub vendor, they will complete the work and submit the bill to us with Basic Value + Service Tax. In this case our HO getting Input service credit on Vendor Bill. Our HO also have ISD registriation and through ISD our HO transfered accumlated credit to our manufacturing unit. Now department is objecting to transfer credit and availing credit at factory, because they said 'your HO is getting credit on erection, purely it is post manufacturing / post sale activity so credit is not allowed at manufacturing unit.
Kindly advice me, if any case laws to come out this issue.