I should just go down there first thing and get a cage and whatever else you need. You can refuse acceptance of the delivery on Tuesday which means the cage gets returned without you having to pay the return postage, although it's a good idea to email the seller first to say you want to cancel the order so are not going to accept delivery - it's what I was advised to do by Zooplus when another cage got here quicker.
I'm just looking on their website
Shame you don't live near me - I've got a Savic Mickey 2XL sitting empty which would be good for a Robo. It is a Robo you're getting isn't it? You don't live anywhere near Durham do you lol?