I think you should try wire transfer option rather than card withdrawal. As I am also registered in that exchange but visa/mastercard withdrawal restriction is not exactly a part of RBI guidelines. From 2010 onward I am in the field of online work. Then also tried withdraw to my credit card but they replied me that in INDIA card withdrawals are not permitted.So , you cant say that it is due to RBI latest guidelines. Credit card and debit card guidelines, terms and conditions do change time to time.