GS order history seems to be working now. I see my recent GoW order.
You should be able to cancel now.
I purchased God of War and Nier: Automata seperately after failing to buy them together. Unfortunately, all 3 orders eventually revealed to have gone through. I managed to have a friend cancel the order with just God of War on it last night. However, this morning the order with just Nier showed up in my email inbox and now neither of us are able to cancel that order. I made the purchases as a guest, so I'm not sure if that adds to the problem. I don't know what to do.