HDFC Bank — address not updated due to signature mismatch

Address:

Bhopal, Madhya Pradesh, 462039

I have been a customer of HDFC Credit card since 2009 and during these periods being a Govt employee I have been transferred to several places. Recently I've transferred from New Delhi to Bhopal and I've requested for address change by filling up form and dropping it to nearest HDFC ATM. The request for address change have been rejected twice for signature mismatch. Now, in between my new card have also been attempted for delivery at my old address at Delhi which has been returned. Such is the cumbersome procedure to change the address is not at all appreciated by HDFC bank. It took much of effort to connect Customer Care through IVRS and she advised to fill up a form for new signature; attach PAN card and submit to nearest HDFC branch. The signature as appearing in PAN card only will be valid. The point is, PAN card is also obtained appx. 15 years back and the same can't be matched. Request you to kindly look into the issue and help me in updating address.