I Chose the Wrong Items In My Order, Yet Watsons Won't Allow Me to Cancel

Watsons purchase is I guess one for life when you click it!!!  can't cancel the order because I chose the wrong item twice by accident. The digital assistant says that the order can't be canceled because it has already been made, even though it has been told that it is being made. But I should be able to cancel it at any time as long as the item hasn't been sent out yet. What's happening is a complete shame, and I need the order to be canceled right away. The inability to fix a simple mistake and cancel an order before it is sent out is making things more difficult, what's even more confusing is the digital assistant keeps saying different things. People who have bought something from you should be able to easily and quickly cancel their order, especially if they made a mistake.