[Resolved]  SBI — Pledged NSC with housing loan not credited even after one year of their maturity

I had taken Housing loan (ac no.[protected]) from SBI Hilsa(code 03587) in May'2008. At the time of its sanction I had given to SBI Hilsa NSC of Rs. 50, 000.00 duly pledged by GPO Nawadah(PIN -805110). Numbers of NSC were 68EE775858, 68EE775859.68EE775860 68EE775861 & 68EE775862 each of Rs.10000.00 Dated 21.12.2006.having registeration no 7421. These NSC matured on 22.12.2012 and matured amount was Rs 80050.00. But even after one year of their maturity, the amount not credited in my loan account. on asking to Branch Manger he each time replies that he had sent the NSC to GPO, Nawadah but not came back. this is from last one year. on asking to POst Master, GPO, Nawadah, he replies after sseing the file that these NSC had been discharged in Feb'2013. I am puzzled what should I do. I am paying interest which would have reduced if these amount credited on time one year back in my loan account. please enquire and justify who is responsible for my financial loss.