Recently, I sent an I.T job seeking friends CV to my manager who said he wouldnt interview as he currently didnt have any open positions even though it was a great CV.
A week later an agency convinced my friend he was getting an interview with my company, I rang my manager and he said he knew nothing about it.
A day later my friend got a phone call from the agency to say my company had the position on hold but wanted to ensure they were working very hard for him to try and get him placed. Agency is well known. This was in last 2 weeks.
Im sure if the position was open theyed get him an interview but its an example of tactics being used to try and get you to stay with the agency.
I job searched during the summer and found
A) several agencies advertising for same job.
B) All agencies post false jobs online to get CVs in.
C) Agencies cold call based on linkedin profiles.
Id suggest getting a list of companies and applying directly. As well as getting more interviews the agencies got me, several months after I had taken a new position I got direct calls from companies asking was I available as positions had opened so it shows that not all companies automatically bin CVs.
best of luck.