RBI rule around credit card transactions and credit card decline
(for India advertisers only)
Adwords support in India seems to have been caught napping with the new RBI regulations kicking in. They should have acted before August 1 and issued an advisory to us ordinary mortals.
As per the RBI guide line & the information provided by CC company or bank, all Master/Visa Card holders need to be registered their card with respective bank or company.After registration before making payment CC user need to create duplicate CC no.with the specific payment limit.

If this is the case, that your credit cards have been declined, here's what you can do:
1. Please download the authorization form here: http://www.google.com/adwords/newsletters/pdf/authorization_form_in.pdf
2. Print and fill out this form in its entirety
3. Attach a copy of the front and back of your credit card
4. Courier the original form and the copy of your credit card to the following address:
Billing & Payments team Google Adwords Pvt. Ltd.
Block 1, DivyaSree Omega
Survey No.13, Kondapur Village,
Hyderabad 500 032
Andhra Pradesh,
IndiaPhone +91-40-6619-5000
Fax +91-40-6619-5101
Over the past month or so, there have been wide-spread complaints from advertisers in India with issues on their credit cards not being processed. it seems to be related to some type of verification process.
The Reserve Bank of India (RBI) seems to be requiring Google to have these advertisers fill out a special authorization form (PDF) and email or fax it to Google India Pvt. Ltd.
A Google AdWords Help thread has a Googler detailing these instructions.

This is due to the increased credit card frauds that happen in the country.
Hence from Aug 1st
A RBI directive has ensured that from August, credit and
debit card-issuing banks must provide for additional authentication of
information over and above what is visible on the physical card. In other words,
the cardholder must key in an extra security code or some other data to complete
a online transaction.
This was long coming as RBI had announced these way
back in Feb 18th.