No notice for out of stock

My kids and I went Mcdonald willows crossing yesterday for ice cream cones.WE ORDERED at drive through and when we about to pay at their next window we were informed that they don't have cones in stock. I asked her if she can pour in her cup as her not having stock for cones has nothing to do with me. She said at an additional charge and I refused as their menu said ice cream cone is 3.90. If Mcdonald is unable to supply and meet demands for the client,why don't you have prices for ice cream but bring your cup or cone? Don't they call other branches and borrow and then they will replace when they have stock?... serve from cups and when there is a loss you will start ordering enough stock... fed up by disgusting service.