Since prayer isn't working I wonder if you tried anything else. Have you tried commanding them to go away in the name of Jesus Christ? Or command them to go away by telling them you only welcome those from the Light?
"The Children of God were moulded by the Hand of God which is called Awen..."
The Kolbrin Bible, chapter 5, vs 1
"But ask now the beasts, and they shall teach thee; and the fowls of the air, and they shall tell thee:
Or speak to the earth, and it shall teach thee: and the fishes of the sea shall declare unto thee."
Job 12: 7 and 8 (KJV)