They gave me wrong order and they took my money and their food

On the 3 rd july 2020 at 17:50 I ordered Pop-ITS and after few mins I sent someone to collect it.to my surprise is a wrong thing that I didn't order ,I called immediately n I explained n they said I must come back to the shop. When I got there I explained again but I was told that they don't have the POP-ITS in stock for some reason and I understood but my problem is why did the cashier never explained yet she took my money.and the manager who I found wearing the streets uniform she never resolved the problem instead she asked me what do I think we must do.I was puzzled as they gave me the wrong order n I payed .I was mad very angry I asked what does she suggest to do ,she went mute .I just left as I was in a hurry without my money n my food that I payed for.