I'm a very new orchid owner. The first one I bought was a drowning Phal. on a clearance table. It had one good leaf but I had to trim off all the roots as they were rotted. I put it directly into "Sphag in a bag". Yesterday when I took it out to examine it, the root stem fell off. The leaf still seems ok and it looks like a new leaf is starting to grow. Is there any hope that roots will form?
I'm afraid that is a goner. If there aren't any roots at all, there just isn't a way to save it. And it sounds like it was already near death when you purchased it--so don't blame yourself. Sometimes they are just beyond saving. Sorry, I know that isn't the news you wanted to hear. :hugs:
Next time, get a good healthy one before the store manages to kill it and you and the plant will be very happy together.