I want the missing items from my order or my money back.

I ordered online for a meal and a drink at Nandos Eldorado Park. They delivered my meal only and didn't deliver my drink yet I was charged for it. I've been complaining and haven't received a single phone call from the restaurant confirming if they'll refund me for my drink or if they'll deliver it! I've never been so disappointed in the pathetic service I am getting right now! This is teaching to never pay before receiving my food from you guys.