I'm sorry but I can agree with you.
Windows Phone 8 wasn't certianly made to work with Yubikey. At least I didn't see that feature in Windows 8 site.
But Yubikey Neo was made to work with Windows Phone 8, and its just that which I can see in its features in its site.
So, the least you should have done was correcting your commercial site, thus avoiding this kind of problems to your inadverted clients.
As you didn't do it, now you must solve your client's problem with the least disturb to them.
See for instance this post in LastPass app for Windows Phone. I'm not the only one who thinks so.
Quote:
by Jason 8/19/2013
Love LastPass, love the app. One issue -- I have a yubikey neo (which can use NFC), and this does not work in the app. Apparently this is a common issue on many phones (I have Lumia 925), sounds like there is a workaround for this available on the internet, but involves significant work and complexity.
As I can see Jason too as acquired something which is good for nothing.
I think that those who have trusted in you buying your product deserve a little more respect than being sent to a forum.