Sterling Tree Magnum — teak

Address:

600088

My father has purchased 1 teak tree of rs 1775/- dated 22/03/1996.
Maturity date of this certificate is 21/3/2016
Maturity amount after 20 yrs is rs, 97500/-

I have no communication from stm or money from them.

What shld i do and how do i lodge a complaint legally?

Kindly advice, as my father passed away : (
No one there help me with this situation.

Kindly help.

Regards,
Sen