Pureit / Hindustan Unilever — No response for over one month regarding issual of duplicate share certificate

My grandmother hold shares in Unilever. However, to demat these shares, she needs duplicate share certificate, since the original one has been lost. It was bought more than 20 years back. However, I took all the necessary steps mentioned by the investor relation department o[censored]nilever. They told me to send request letter to Karvy Fintech Hyderabad. I have done all steps and then there is no reply to my mail. All the contact number mentioned in Unilever website does not connect me any person, doesn't respond to any mail also.