Blue Dart Express — Lost My Shipment

I had shipped a carpet through Blue Dart on the 23rd December 2021. It was an amazon self-return shipment. I received a notification on the 30th of December that my shipment had been received.

When I contacted the vendor with the confirmation they told me that they had not received my shipment. I even shared with them the name of the person who signed for the package and they told me no such person works there.

Immediately I contacted Blue Dart about it and they said they will investigate the matter. They even gave me a reference number M[protected] Its been almost three weeks and no clear answer.

What is the course of action I need to take to help resolve this issue. Any suggestions or ideas are appreciated.