Infrastructure Development Finance Company [IDFC] — DD issued in wrong name

Hi

I have invested in IDFC infra bonds 10 years back and on maturity they sent a DD but with a spelling mistake in my name.
When I contacted them to correct the mistake and arrange to send me a new DD with the correct name and that I am ready to post the previous incorrect DD, but they kept on sending me emails about a list of documents and forms to be submitted, they haven't even sent me the forms they are talking about.
It appears to me that they are trying to avoid giving my hard earned money back and that the spelling mistake in the name has been a deliberate attempt to avoid paying my money.

It's a mistake done by their staff, they should correct it by sending me a correct DD instead of asking me ( after 10 years ) to submit number of different forms and documents. They have my foilo number and all the information already with them, which is sufficient to issue DD in the proper name.

Please I need help in this matter. Any help will be highly appreciated.

Thanks
Sarika