Delhivery — Missing item(box)

Address:

Delhivery warehouse, Kaikuchi,Assam

My father had booked a box of home utensils and personal equipments asking with a cycle from Nabadwip, West Bengal to Assam (to me) on 17th August, 2020. After repeated requests they delivered my cycle but not the box. I insisted them to deliver it at earliest, but they did not pay heed to. After almost 2.5 months I physically visited their warehouse and after 3-4 hours of searching I came back empty handed. 2 days later they told me that my box has gone missing. I asked for compensation. But, they told me that they won't compensate for household items.
My concern is that they acknowledged their fault but refused to compensate. How could it be so. Even I received a call from Delhivery after acknowledgement of missing items about the approximate cost of those missing items.
If you could help me to solve the matter it would be a very much help to me to solve this riddle.

I have attached photos of taking delivery of my cycle, a photo of the person came to deliver my cycle and a photo I sent a personnel there (delhivery warehouse) showing my box(which they never delivered).