I am having the same issue. My son's computer was logged onto via the phantom account and he "left it at school" so I marked it as missing. Next day he got it back, but even though I marked it as recovered it automatically logs onto the phantom account when powered up without offering any other account choices, and while in the phantom account, it appears to be the only account on the computer. How do I get back into the other accounts?
I tried reverting to missing and then back to recovered several times, with his computer connected via different wifi hotspots to no avail. This is a brand new computer just given to him last week, and it is locked so that I can't install anything on it, and he can't get to his work he stored on it. All it can do now is browse the internet, and it appears I can't even restore it to the factory original configuration because it is locked out.
How do I fix this?