First, let me say that there are *very* specific instructions you need to follow to get your money back in the event the code does not work. If any attempts were made previously to unlock the phone then the number of previous attempts needs to be videoed/imaged. Then you need to *video* you putting in the code into your phone to see if it works. If you don't, you lose your chance to get a refund. Not all phones have the original number of code attempts left - sometimes the previous owner tried a few times, and this leaves you stuck. I believe if you have less than 5 attempts left you need to document.
Anyway, after 12 hours and a few updates, I got a working code for my Moto X 2nd gen. Thanks!