Month end without cooldrinks and bad customer servise

On Friday the 31/07/2020 I went to McDonalds Avonwood to buy supper. We went to the drive thru, while busy placing the order the cashier advised that they dont have any cooldrinks available the only thing they have is Powerade, I decided that I'll take the powerade then cause what's the use of ordering a meal but there's no cooldrink. We then went to the payment point paid for the meals and then noticed that I've been charged extra for Powerade even thought the business dont have any cooldrink available. When getting to the collection point I've noticed that the customers inside the store is getting cooldrinks but not the drive thru customers, I then asked the girl at the window why we cant have any cooldrink if the in store customers is getting and she ignored me flat. I feel that if you know it's month end you as a store need to make sure that you have everything in stock and if not then the business needs to compromise and not the customer, and I feel the way the girl at the collection point handled us was wrong as you don't ignore customers if they ask questions and to top it off they did not gave my son his toy with his happy meal. I think that Avonwood branch need a serious change of management as that's not the type of customer service given to any customer, what's the difference between in store customers and drive thru customers as both are paying for their meals.