As others have stated above the original blue was pumped full of magenta, so if they don't have their printer profiled at all or are using the wrong one, I have no doubt that this could easily turn purple.
What Vohaul did was he cut the magenta nearly in half and put some black in it to darken it back up, this should theoretically work with taking the magenta out.
I would also ask the printer wtf they were thinking releasing something that was obviously meant to be dark blue when it printed purple. I sure hope you didn't have to pay for those 3 reprints. I understand not doing an exact PMS color match with a gradient as some programs this is very hard to do, but to not even get in the same ballpark is a bit disgusting.