Sometimes these things can take a long time. I had a rootless paph that I almost tossed, but after 8 months it finally decided to live. Then again, I had a rootless Angraecum leonis I tried everything with short of taking it to bed with me at night. It would grow a few roots and then they would croak, grow a few, then croak. I can't remember how long I put up with that nonsense, but finally the compost bin called and I gave in. I didn't regret it.