Sonic — sonic app

I use the app to get the happy hour drinks half price. Sonic is expensive and I could go elsewhere, but love sonic. This morning I ordered a drink on the app and a pop up appeared saying I had to make another purchase to receive that order!!?? I added another drink and it came up again. Just to check I added food and bingo!! It went through. I did not want food!!! I checked the infor on the app and it said everytime you use it you get drinks happy hour half price! I took a picture. That is false advertising at the least!!! I am very upset, even though the cost is not that much. I can go elsewhere for diet coke, but I don't want to. This is a hook and I don't think it is right. We should have a warning if they are going to change things.