it does work ... but it is headache..
first - contact bank if they do not reply.. tell them that you are going to banking ombudsmen ... they will come back to u in 1-2 hours..
then they will ask for the form to be filled and stuff..
and the inquiry begins...It will be a long fight .. but u stand your ground that the services offered is not working .. keep all communications in writing and also file a case in police station .. (last step if all fails ) and do file a complain to banking obdumsmen too..
I had success with hdfc credit card but the vendor was supporting after a police complaint