I suggest making it to random book studies (and meetings). This works better if you have more than one congregation in the same hall, since they might see you at the other meeting occasionally. Do not make it easy to guess. Once you have the pattern established, you simply start skipping all the meetings that week or that session. Increase the number of skipped meetings.
If they waste the time calling you, there is a very simple solution. Yes, it is rude. The phone has a hang up button. If you answer the phone, you "accidentally" hit that button. That will disconnect the call. You might want to unplug it from the wall, so they might think you have a telephone blackout. Or, just don't answer it. Either way, the call will become wasted time.
If they visit you, now it's time to play hardball. The options are (1) not answering the door, (2) answering with a specious reason to cut the call short, (3) answer it and warn them that the next time they hound you, you will not ever go to any meetings, ever again, or (4) if they continue hounding them, warn them that the next time you will send in a disassociation letter. If it gets to the point where you just don't give a fxxx about your standing in the organization, you might also come to the door with a Ouija board, a copy of Crisis of Conscience, or some Christmas decorations (they work great when it's out of season to drive hounders berzerk). Then, if they try to haul you in for the judicial committee, just don't show up.
Or, if it gets to where you don't give a fxxx what happens to you within the congregation, you can point blank threaten that one hounding and you will never ever be going to any meeting or out in field circus ever again. And, you could threaten a disassociation letter upon any houndings. That should do the trick, but you will probably be officially put out of the congregation at that time.