Excise duty in return

I am working in a sanitary ware manufacturing co. we sale item to a trader against c form after some time he not pay the full amount against the bill outstanding so we took back the some part of material from his godown against he challan bill of his trading co. now is the question that we can took the excise and cst on the material is took back in return as sales return or not and what is the procdure for that excise and cst.