Acknowledgement itr-v submit after due date

I was file ITR-4 for A.Y 2010-11 with Rs.49540 Refund on 30.3.2011 but  ITR-V is submited after due date on 30.8.2011. so I not recieved ITR-V Reciept and No claim Refund.  please tell me what  i can do next ? so Return become valid.