PPF — PPF prematurely closing by SBI

Address:

490006

I opened A/C of PPF in SBI Bank, Indira Place, Bhilai, Chhattisgarh, having branch code - 574. My PPF A/C no. is [protected]. I received SMS on 20th march 2016 from SBI bank for giving instruction for continuing the a/c or giving maturity instruction because a/c was maturing on 31st March 2016. So I approached my SBI branch and filled up the form on 31st march 2016 giving instruction to close the a/c after maturity. But the staff of SBI closed the A/c prematurely on 31st March 2016 which resulted in loss of my one day interest of Rs. 1750/-. Sir, pl. guide me where the PPF a/c can be allowed to be closed prematurely? Loss of money is not the concern for me. It was the negligence of the staff which is bothering me about the trust with the bank. The staff first accepted the mistake & was ready to pay the money but couldn't.
Later on after couple of few days I approached Branch Manager but he also refused to pay. It was a matter of one day only, instead of closing a/c on 31st march 2016, the staff could have done it on 1st April 2016. Branch manager replied as the application was on 31st march2016 so his staff closed on the same day. Branch manager says for the new a/c holder, he is always ready to close PPF new a/c after 2 years also prematurely which I think against PPF maturity rules.
Pl take up my issue seriously. Rs. 1750/- is small amount and even if my bank doesn't refund me, it doesn't bother me. But they are doing their job against PPF rules.
In this scenario either System shouldn't have allowed to close the a/c of PPF prematurely or staff should have not done this mistake.
My only fault was I filled up the application form to give instruction of closing the a/c on 31st march 2016 after maturity instead of on 1st April 2016. Bank branch manager and grievance cell of SBI says according to new rules of PPF, a/c can be closed any time prematurely.
Kindly settle this issue so that nobody can loose hard earned money in future.
And on this issue pl. clear it whether it is my mistake or bank staff.

Thanking you Sir.

Awaiting for your reply and guidance.