Excise reversal for shortage receipt by customer from tpt.

Dear Sir,

We are sending material to some location in south to OEM. Its generally picked up by customer convenience from transporter. During the year customer has received short material for value 200,000 including excise and cst. Now customer is not giving any invoice to reverse the duty, they are only issuing ODC (open delivery certificate) mentioning short receipt. Is this correct to reverse the excise or any procedure to deal this situation? Waiting anxiously for your reply at amitkrmakharia @ yahoo.co.in