Infrastructure Development Finance Company [IDFC] — Non receipt of redemption amount for folio no. IDB0297425

I am holding physical bonds of IDFC longterm infrastructure bond tranche 2 and matured as on 21.02.2021, the redemption amount has not been received as on date even after several emails communication starting from my first mail on 23.02.21 and continue between me and Kfin Technologies Pvt Ltd on email, einward.[protected]@kfintech.com.
I had also sent the PAN card copy and cancelled cheque copy
I had received a mail also on 15.03.21 intimating that the warrent/DD sent to me was returned undelivered and a link was sent to update the details but upon trying to update on the link it indicates always runtime error at last submit page. The same was communicated but no reply or advice how to go further and again the last mail on 25.03.21 saying that the warrent/DD sent as on mature date which I have received several emails with same content.
Pls find dates of emails received at my end:
26 Feb 21
01 Mar 21
02 Mar 21
05 Mar 21
08 Mar 21
11 Mar 21
12 Mar 21
15 Mar 21
16 Mar 21
19 Mar 21 & 25 Mar 21