Material Type Mismatch -- Error message

Dear Sir,

A wrong entry ( GR) done by the end user in T. code MB1C Movement type used 532 before the 531 for the process order in different material type means process order header material is SFG Imported to SFG Indian, so a material document have generated for this , Now it is the wrong entry and we have tried to canceled by T. code MBST and MB1C t system through the error message with no message type and help -

Material Type Mismatch.

How we can cancel this type of entry for nullify the movement in process order.

regards

ALOK