Where is the "new" Last Watch?

[Txlonestar]

I'm looking for a few answers and hoping someone out there, that is a fan, will hopefully know the answeres to my questions.

I'm sure you the fans know that Sergiei has released new cover art for the series, which included the newest edition to the series "The New Watch." Which I'm about halfway through reading at this point, Still loving the series!

I'm wanting to get the books with the new cover art to have a complete matching set including the 5th book. I have not once been able to find any new cover art for the The Last Watch. It seems that this book doesn't exist anymore except online. I'm very confused by this.
Why was The Last Watch not included in the new cover art?
Sergei doesn't even have this book on his official web page. At least not the English version.
A lady at Barnes & Noble said that it's possible that the cover art was not up to par or finished and that could be why it has not be released, which is what I'm hoping for in the long run.
Any insite to this would be greatly appreciated.
The Last Watch

[Ken]

Just began New Watch this afternoon. I have the same questions, but would prefer New Watch in the older cover style. I don't mind having multiple sets, but would like both sets complete.