I'm an inexperienced researcher and I made the stupid mistake of submitting my article to a predatory journal. I realised the journal was fake when they failed to provide the reviewers comments.
I then requested that the article be withdrawn. I received an email back from the 'editor' saying that the article had been withdrawn and guaranteeing that they wouldn't publish the article without my permission. I didn't sign the transfer of copyright, pay any money and the article hasn't appeared on their website.
My question is whether my article is now a write off? Can I resubmit it elsewhere or just write off as a bad learning experience? I would really like to salvage if if possible.
You can now submit it elsewhere. It has not been published and it is not under consideration anywhere, so you are free to resubmit it.
The fact that the first journal was predatory is only relevant because that was the reason you withdrew the paper.
Put a version of it online - on your homepage, or better yet a place like ArXiv. If it gets published by somebody else later you would be able to demonstrate earlier publication. If you chose to put the article on your home page, it is strongly advised to go to https://web.archive.org/save/http://homepage.my/article.html to have it saved and stamped in the Internet Wayback Machine. Another option with a record of date of upload is a repository management website like github.com or bitbucket.com.
Talk to one or two central people you know personally in your field (and with whom you have a sort of friendly relationship). Tell them this happened to you, and ask them for the favor of looking at the paper. While this would preclude them from evaluating it as part of a program committee/editorial board, it would ensure they would back up your claim against a publication of the same work by someone else.