Poor service

I had an online order from MR D food, because my order didn't have sides, I went to queue so that I can pay for the sides before collecting, then I told the lady that I needed to go wait from the collection side. I waited there till I went forward to ask about my order since it doesn't appear on the collection screen . The guy who giving out orders tells me that I should have just came forward and not stand. So now how was I going to know that, couldn't the lady at the till pass that information to me. This was poor service to me. And they didn't even see that they are wrong since theres no communication between themselves.