GoAir — lost baggage at delhi airport

I had lost my baggage at delhi airport. I did not get my checked in baggage after my flight. I had travelled on 16/12/18 by flight no g8 -465 from mumbai to new delhi. It was dark coloured trolley bag. I had filled the pir form at the airport. They had told me that they will call me but no one called me. After calling for many times, the next day somebody picked up the phone. They told me to wait for 5 days. Then also they did not call me. It has been 9 days now. No one has called. I had my valuable clothes and acc in it. I think i have to take action against such irresponsible behaviour of the airline and file case against the airline