Karvy — Signature mismatch while submission of physical shares for demat

I have some physical shares which i received about 25 years back.

I want to convert he same in my demat account with ICICIDIRECT.
to my ICICIDIRECT Branch . However the shares were returned to me by KARVY COMPUTERSHARE with reason signature mismatch.

I wish to apply for change of my signature . I DONT KNOW WHOM TO CONTACT.

I stay in Pune City. I am a senior citizen.

Please help me in this regards.

My mobile no is [protected].
Name: Niranjan Chiddarwar
mail id: [protected]@gmail.com