Zomato - food package was opened when deliverd

i have ordered biryani on Zomato (order number : **********) to my office, as usual the delivery guy called me up and started bugging me where is my location, i had to take a moment and guide him to my office, only problem was he was not checking the address in GPS, or he was reluctant in using it, he was like directly will call and ask him the directions.
later he left the parcel at my company security desk, when i collected it, the food cover was opened, i took images and later i contacted zomato about this, one of their colleague promised me minimum refund of **.** when i asked to completely refund it he said minimum he can refund is **.** as it is packaging fault.
Then suddenly in my Zomato app goes offline but I don’t know why and how. It was the only app which became offline, I was surprised, then which I logged in again for chat, another guy came in I repeated complete story. He started asking for images for which I was not able to share them through chat, I asked him to give me another source to share you the images. He didn’t give any another resource and started blaming me and shaming me that I am lying and faking it.
I am frustrated with his words, I lost my lunch. Left hungry. They are not refunding me anything, I lost complete faith on felt mentally disturbed and starving without any refund. Please help me on it.