What exactly was this credit exploit? I saw it mentioned on the dev site, but don't understand what was happening?

seems i can't delete this post, but i found out the problem...

A few days ago, I hunted down each datacron on Coruscant and after I got the last one, no achievement dinged, and when I looked it up, it said I was missing one even though they are all lit up on my legacy. I even went back to the "missing" one which said I could not get it again. I reported a ticket in-game but recieved no response. I would like this fixed please. I'm sure this isn't the 1st time this has happened before. Thanks in advance.