The answer is not in trying to effect deliverance from these harassing spirits, for that will only bring temporary relief if their mode of access to harass the believer's soul remains open and available. This is one area where Christians often overlook the obvious. Satan does not just have one harassing spirit to send, one singular spirit that could be bound or rebuked or cast out and the problem of that person's harassment is over. Satan has far more spirits to keep sending through open doors of access than any human being has time to deal with and still find any kind of life outside an ongoing spiritual survival mode. When Satan can get you in such a "spiritual survival mode," he knows that you are effectively prevented from focusing on pursuing your destiny with God. You're totally focused on him and the ensuing spiritual warfare. Hello? That is his Satan's whole intent in harassing you: TO KEEP YOU FROM FOCUSING ON YOUR RELATIONSHIP WITH CHRIST AND THE FULFILLMENT OF YOUR DESTINY PURPOSES IN GOD! 
To continue to war with Satan over spirits he is sending to harass you is like trying to mop up an overflowing toilet without ever turning off the water pouring into the toilet tank. The permanent answer lies in stopping the inflow of what you're trying to deal with or clean up. Otherwise you are just continually mopping up the mess, never coming to a permanent solution. In the unsurrendered soul, a permanent solution occurs when you close the doors of demonic access brought about by your own stronghold thinking (also explained in Shattering Your Strongholds and Breaking the Power). This involves using the binding and loosing principles of prayer (as referenced in Matthew 16:19) to free yourself from this cycle. Bind your will to the will of God, bind your mind to the mind of Christ, bind yourself to the full truth of God's Word. Loose (crush, smash, break into minute fragments) all hindrances and devices the enemy is trying to send against you, loose wrong patterns of thinking you have, loose wrong beliefs you have, loose the effects and influences of wrong agreements you have made with wrong teaching, and loose all of your soul's stronghold thinking patterns. Do this every time the enemy launches another attack against you. You will see victory! Please refer to the books for further explanation. Rev. Liberty Savard