Central Bank Of India — not refund money in bank account

Address:

No:34|26 E salt road Marakanam, 604203

I have ordered back case from amazon for 300rs. But i have return it on 21st february amazon has send me a message that money will credited to bank account by 3 to 5 working days but still money is not reflected in my bank account. I have contact to amazon customer care they saying that money has refunded to bank and also they giving the refund reference number. And i contact to central bank of india customer care and asking about these issue they saying to visit home branch. My money was hanging between these two problem please refund money in my bank account.