@MartinT
Well, judging by the toc, I would say, that you can send in any phone, without getting a refund, except from Norway and Switzerland (maybe that’s the reason for the problems with entering a delivery address).
And it seems to really be a good thing to do, as they revive phones, that are still working and recycle those that don’t. The recycling value will be used for enhancing recycling programs:
Contribute to develop recycling
We work with our partners Closing the Loop and Recell Ghana to ship e-waste from Africa to Europe for safe recycling. If you send us a phone that can be reused, the revenue beyond costs, if any, goes to financing those projects.