It refund returned to bombay

  GOOD MORNING SIR. ...THE IT REFUND CHEQUE OF MY SISTERS HAS BEEN DISPACHED  STILL DIDNT RECEIVE THE REFUND CHEQUE TO THE ADDRESS ACCORDING TO UR RECORDS..THE REFUND STATUS SAYS WRONG ADDRESS..BUT WE DIDNT RECEIVE THE REFUND OR THE POSTMAN CAME TO THE ADDRESS..WHILE ENQUIRED IN P.O THEY SAY THAT ADDRESS WAS WRONG AND IT WAS RETURNED TO BOMBAY...NOW HOW COULD I AGAIN GET MY SISTERS REFUND BACK...COULD YOU PLEASE MENTION THE PROCEDURE??PLEASE..AND I WOULD BE VERY THANKFUL TO YOU...