applicant tree job applications are posted but the jobs don't exist.I have spoken to some of the companies listed and they know nothing about the jobs Internet

I have been looking for a job for a long time.I have been to many websites.When you click to apply a lot of these sites have the application pop up as an APPLICANT TREE job application.The form is always the same and asks the same info.It asks how you would like to be notified about your application.My choice is always by email in 2 to 3 days.I have never been contacted.So I started calling some of the companies offering these jobs.I have spoken to" SEVERAL" reps. from these companies and not one has any idea what these jobs are or where they came from.I have sent countless messages to APPLICANT TREE via there contact tab at the bottom of their application form.After submitting the message I get a thank you and they will contact me in 2 to 3 business days.I have never heard from them.Are they and their jobs legit?