product cost

Dear Experts,

Could you advise me in the following senario

While extending material ,I input the standard and variable cost incorrectly as 348.2 per KG EGP instead of 0.34 EGP.

A process order 104568508 was created and for the material. The material was despatched on SAP.

After despatching we noticed the error as variance. We modifed the cost and after that we made goods returned. So the material was despatched with the huge cost and returned with correct 'low' cost which caused a huge loss on SAP.

Regards,