Swiggy — Refused to refund for incomplete order

I placed an order id. #[protected], i got a delivery maybe around 30 mins late. It was not an issue for me. But in that order samose worth rs. 165 were missing. I immediately talk with swiggy chat help section. They said they will look into it. After few mins they have sent me 100rs coupon. When I again tried to talk to them they have given some absurd answers. That now we can't do anything as coupon has already been initiated. When the order of 165 rs was missing out off 410. Why they are forcing a coupon to me??? I tried to talk to them 4'5 times and i got same response with no help. Even when I tried to open the chat again.. few important messages about my complaint are missing. I have all the documented proofs as screenshot. What should I do??