HDFC Bank — Signature Mismatch and address change

Dear Sir,

My name is chanda bakshi and i am a customer of this bank from past 5+ years. I have a hdfc credit card account not a saving account. I left my job and i want to change my address. I already send a address change form but due to signature mismatch my application is rejected. I mail on several mail id's and i got a reply thet first change your signature then address. But when i talk to hdfc branch they said we are not change the credit card signature. I need my card urgently because my previous credit card had expired. I do not know why they people makes too complicated for credit card users for any profile updation. Please resolve my issue

Regards
Chanda