... it’s still on me, isn’t it, because presumably I should have requested them first? 
Paid a deposit (on credit card), received T&Cs, emailed back signed order confirmation with balance due on delivery of goods. In that order. Have only just clicked, because clearly I’m a twat, that we probably have no right of cancellation. Timeline was over the last five days.
We’ll make it work but I’m kicking myself. Such is life and damn idiocy