Kfintech — Kfintech not giving money back on bond maturity

I purchased infra bond “IDFC FIRST BANK LIMITED - INFRA BOND TRANCHE 2” with Folio number: IDB0290199 in year 2011, which got matured in Jan 2021. Trying to get my money back from kfintech https://www.kfintech.com/. Originally they said, they sent a check to my home address. The tracking via Aviral logistic keep showing “Left Mumbai” for month and it didn’t reach my home. Then Kfintech asked me to provide cancelled check of a bank account, and I provided ICICI one (NRE account – my bad, I will tell you in a while). Now, its two+ months, they keep saying we have successfully deposited the money, and my account didn’t receive it. 30+ follow up, same response. Their all phone numbers are not working at all, so only option to communicate is email. Checked with ICICI and they mentioned that NRE account can’t accept Indian currency (This is why I originally said “my bad”). I keep on explaining this to Kfintech that if NRE account can’t accept Rupees, how come you successfully transferred it.. but again same standard ROBOT response “We have successfully transferred the money to your account, please check with bank.” This is going on for about 3 months now…. With no hope to get my money back ☹ Can you please help? There seems to be many such complaints about Kfintech in social media which they don’t care to address.