Well, if in the credits page they already misspelled "translator" and the cover has not been even touched, no wonder the guys that most likely were putting an effort got mad. Quite drastic, but unless there are serious issues with the current group's work (and your version lacks those), two groups started at about the same time, the previous group dropped it or it has been out of commission for a while (way more than a couple of weeks), it's never nice to hijack a series.
I don't know how desperate for attention are the people who do things like that.