I understand your relief, and congratulate you on squeezing out some payment, but I still feel obligated to give you a last piece of unsolicited advice.
I used to work for this crazy outfit, too. While Essaywriters.net paid me somewhat regularly when I began my employment with them (this was in mid-2006), by 2007 they'd begun to song-and-dance me, paying me late or only partially, and by the end of that year (2007), they began their present strategy of never paying me at all. My husband and I have virtually lost track of the amount of money they owe me because of their constant policy changes over the months I was regularly writing for them, and their weird withholding practices and random payments which followed no predictable pattern.
Clearly I've ceased writing for them, although I keep my account active in case, by some unlikely miracle, a dime drops into it some day. I know it's a relief to get money of any kind from them, and, again, this is unsolicited advice, but I think you should not only hold off on writing for them again until you see the remainder of your money, but forever.
Once you see the rest of your money, then frankly, run like hell.
That's just my advice from one who's been burned.