Occasionally you may need to cancel an Amazon (UK) order that’s “dispatching soon” – on doing this Amazon say they’ll “attempt” to, but then a short while later you get an email telling you in fact they can’t, and to refuse delivery or print a return label.
The solution in this case is to change the delivery to go to an Amazon Hub locker rather than your home address. This avoids you having to print a return label, then take it a shop (though, for the record, there are now printers in the some of the shops which are easy to use, and the shop will package it for you – in reality in my experience this means put it in an envelope – they don’t have a full selection of packing materials for fragile stuff).
Sending to a locker it means if the item is not collected within 3 days, Amazon automatically take it back again. Arguably this should be better from the merchant’s perspective (in the case of Fulfilled by Amazon orders) because the package hasn’t been opened, and Amazon are aware of this, so it should be able to go back on sale without further intervention or cost to them.
Curiously, in the UK this doesn’t appear to be possible from the website yet, only from the iOS app. But as soon as the order is visible there you can change it from your home/business address to an Amazon Hub.