All you're doing is repeating a known false teaching. I have debated with many on this very same thing that you are claiming. This teaching is not something that you came up with, but what you have been deceived into and have adopted. It's just a false teaching.
Satan was not bound in the Abyss when Jesus began teaching, for Peter said, that your enemy the devil, prowls around like a roaring lion seeking whom he may devour.
By believing in Jesus, the law no longer has any power over the believer, which was ammunition for Satan and the powers of darkness and that because mankind couldn't met the laws righteous standards. We are now free in Christ. However, the god of this world is still blinding the eyes of those who are rejecting the gospel. Satan is not bound.
Regarding the scripture you quote above, Jesus said that because the Pharisees said that he was casting out demons by the prince of demons. It doesn't mean that the millennial kingdom had come. How you people misinterpret and distort the word of God.