India Post — Non delivery of my ignou books

I'm a student of Indira Gandhi National open University, Delhi My study material dispatched through India post on 29/01/2024, as per the india post online tracking system it arrived jhilmil post office on 01/02/2024 and the website is mentioning that the item is delivered to addressee but I've not received my books till now. I approached jhilmil post office they give me contact number of post man but he is saying - I don't have your consignment. My consignment number is CY[protected]IN

Kindly help me to get my books because my exams are approaching. Thank you