Reversal of Cenvat Duty

Hi Expert,

Please suggest while doing GRN manual excise invoice is captured but by mistake user changed the material type from Raw material to consumables and then after done part 2 and MIRO on January 2014  which result  into system has captured 50% of Duty and availament of cenvat utilization is also done.

Please now suggest what will be the appropriate step and what should i follow.

Regards

Gaurav Maheshwari