Why Georgia
I don't think you realize that the one being hurt the most by the stress is yourself. If you continually feed upon the bitterness and hatred you are the one who suffers the most. It is not the Jehovah's Witness who called upon you since he has already probably forgotten the experience...or has remembered it only as a story to share with other JWs to reinforce their belief that they are God's chosen.
On the other hand, kindness and compassion are always good qualities to cultivate. Put yourself in that JW's shoes. Would you have taken time out of your schedule to warn a neighbor of impending danger? Would you sacrifice time and money by sharing what you think important with others by calling on strangers' doors? This is what Jehovah's Witnesses are doing whether you agree with them or not.
If you are still annoyed by their behavior, have you thought of putting a small sign on your door requesting that Jehovah's Witnesses not call? There are ways to handle these matters without the anger and hatred.