I will be glad to know how the p.p.f interest calculation is done.I have opened an a PPF account in SBI and have deposited a sum of 3500 last yearie 2012 but received only Rs 73.00 as interest on 31st march 2013.on inquiring the rate of interest is 8.00% so it should be Rs 280,is the bank paying me less???? if so where to complain.