Indigo Airlines — Bag lost / claim

Self Flew from Port Moresby to Mumbai using PX/Qatar & Indigo airline being partnered airline with one singly through ticket.
My baggage has not come since last 10 days and now indigo airline is washing off their hands saying u ur self need to check with other airlines.
Such a bad service and i dont know where my bag is and they also dont know.
Only stories saying qatar 8000 bags are stuck and they are not able to trace it.