IDBI Bank — idbi infrastructure (tax saving) bond (2500a) how to get the maturity value

Sir/ madam,
I have original certificates of 4 bonds of idbi infrastructure bond (2003b)-folio no-16ifb1794078 and 6 bonds of idbi infrastructure bond (2005a)-folio no-22ifba2879530,
Original certificates are available with me. Till date i have neither received maturity payment nor any communication from bank regarding maturity payments
Please let me know
1. How to get the payment of maturity
2. Where to send the certificates (Scanned copies attached herewith)
3. Whom to address the letter
4. Details of other documents to be attached (If any)

I am eagerly waiting for your reply.

Tarun kanti barik
([protected]), email id - [protected]@rediffmail.com