Tds refund possible?

I have invested in FD in bank on 1-4-2011 for 1.5 years of Rs 3 lakhs. Intres in FD is rs 40,500. Bank have deducted TDS but FD is not yet matured. *my q. is tds deducted can be refunded or not? (bank refused to me that it is not possible now and said that if you have filed form 15G before 31-3-12 then TDS would not be deduct.)