Flipkart — Flipkart reject courier return SPF claims even when we submit required proof. Baseless claim rejection without any proof

I am a Flipkart seller since 1 year. Multiple times I have lost products in courier return. Even I went to flipkart warehouse to tell them about products being stolen in courier return. Flikart does not approve claims for courier return products. Recently, it happen again and I lost Realme smartwatch S which is a very costly product. Flipkart rejected the claim giving the reason that it is courier return and nothing has happened at their warehouse. How can Flipkart so sure that employees do not steal/replace the valuable products in logistic warehouses?
This has happened enormous time and I lost a lot of money because of this unethical and fraud practice by flipkart.