Vanity-published novel (hopefully) turned into screenplay.

I promised I wouldn't talk about writing issues for a while, and it's only been a month, but then, this is the blog of Samuel Ridings, Author.  I guess I would've either made a great politician or a really sucky one, depending on your wing.
One major mistake I made just before my breakout as Ross S. Simon (maybe by a couple of years) was fall hook, line and sinker for a vanity-publishing scam in which I paid a three-and-a-half-thousand dollar "editing fee" to have see print this novel I wrote which needed heavy restructuring, anyway.  It was an episodic piece about late-1960s generational strife entitled "A Peace of the American Pie." I tell no lie.
I believed my "publishers'" promises right to the end, even paying an additional fee for 25 copies in hardback of the edited novel for myself.  While I still give those away as gifts here and there, I can't believe I would have had my head stuck so far into the clouds of optimism, even around about ten years ago, as to expect the best from the swindlers I was dealing with.  You'd think the sound of that "editing fee" would have set me running.
Well, I would like to think it's not too late.  I'm trying if I can to turn "A Peace of the American Pie" into a screenplay that I could one day direct myself as a movie.  While this may seem too ambitious, I'm just doing it tentatively, in case there's no real hope, but I would like to think I can legally find my way around anything that the scam artists think they've ruined the novel for me regarding, since I never learned too much about what happened to it with them.  Did they really take my money and run?  I wonder if they'd try to sue if I tried to make the film.
Wish me luck.  I want to know that for "A Peace of the American Pie," it's not too late.