Swiggy, And Subway — Missing food item from order

Address: Patna

I ordered a paneer tikka signature wrap and diet coke from subway through swiggy, the wrap was eligible for discount but coke was not, I paid full 67 rupees for the coke and it was missing when I received the order and that too the order came very late when I complained to swiggy they resolved ecery query and chat without even giving any explanation, I emailed them and they say they can't do anything about it or give me refund and the subway people didn't put their number on the internet I somehow found it and called them, they said they will look into it and inform me but they are now ghosting me. What kind of behaviour is this for a customer? I paid but I didn't received what I paid for and these people are acting like they don't owe me anything. My resentment towards swiggy is extreme they are taking platform fee from me and also the 18% gst on it and yet when these kinds of things happen they don't issue refund, compensate or even apologise. Isn't this injustice? These corporates think they can't get away with injustice.