Procurement certificate cancellation

Rajaram M (Asst. Manager Materials)   (180 Points)

02 March 2010  
Actually our company is in SEZ, We are supplying good to 100% EOU vide procurement certificate. After the Union budget 2010, excise duty is amended from 8% to 10% with immediate effect. Now we are unable to supply against the open PCs, What is the procedure to cancel the Open PCs, Please advise me.