Udaan - Quantity of Product missing from parcel

I am merchant on Udaan and sold * pieces of necklace each amount Rs. *** to buyer but due to some reasons this parcel returns from udaan without reaching buyer. When i opened it in my warehouse in presence of delivery man there is only one piece present in it and other * is stolen. I Complains for same to udaan care they first said that we cannot going to consider your complain as you cannot put remarks on POD that you received only * Piece. I told him that i already remarked same. They send me soft copy of POD in which there is no remarks which i already puts. After thinking i understood the matter and came to conclusion that it is trick of Udaan staff. I ask care to investigate matter properly as this is fraud from their employee and investigate with the original hard copy in their records. But each time they provide me same soft copy and replied we cannot able to assist you further. But the fact is i already put remarks which is present in hard copy if Udaan care wants to investigate, Delivery man is also proof of the incidence as i opened in presence of him and i also provide images of empty parcel but each time they are not ready to check hard copy of POD in their records or investigate with delivery man and provide reply (We cannot assist you further). I also ask delivery man to provide me hard copy, he replies he can provide me once he reach office but after that he stop receiving my call. Udaan care also not responding for my requirement to give me hard copy of my POD and investigate matter by directly investigating with hard copy or communicating with delivery man. At last i came to understand that he wants that i get tired and forget this case by not giving any proper replies and support on mails and even on customer care call from * days.