Banks can't escape from their responsibility to provide real reasons for rejection of your loan application. RBI notification dated 6 March 2007 (Guidelines on Fair Practices Code for Lenders) clearly states that in case of all categories of loans irrespective of any threshold limits, including credit card applications, banks/FIs should convey in writing the main reason/reasons which, in the opinion of the bank/FI have led to rejection of the loan applications. You can download this notification from RBI website.
You should first give a written request to bank for return of your money and ask them to give reasons for rejection of your loan application. If your issues are not resolved up to your satisfaction, you can approach Banking Ombudsman at Bangalore with a complain. Beleieve me bankers are really scared of Banking Ombudsman. The procedure to file a complain with Banking Ombudsman is also at RBI website.