Short and simple? I advise against doing any business with narcissisticvert on DeviantART. They commissioned me for a badge well over a year ago, when I was doing them for AC last year. I finished the badge, since they were somewhat small and simple and I was dumb, but she never paid. It was only $10, not a big deal, but regardless... many notes and a year later and I still have this badge hanging around that I don't want.
She responded to a few of my notes of inquiry, acknowledging that she had been flaky and would get the money out soon, get the money out soon, etc. etc. Eventually she just started ignoring my notes. I know she's read them, and she's online frequently.
So yeah. She doesn't follow up on payment. Simple as that.