I'm deeply sorry if you have been stumbled by some-one inside the congregation. I myself have been stumbled in the past. If you have studied the Bible over some time, you will know that Jesus gave an illustration about the weeds; Matthew 13:24-30 This illustration is talking about people inside the congregation that call themselves "Jehovah's witnesses" but are really imposters,even if they are baptized.Some elders are also weeds or "rocks hidden below the water"Jude verse 12. If you carefully read these scriptures you will see that these imposters are "planted" in the congregation by Satan the devil.
They are left inside the congregation until the "harvest" when they are ripped-out and tossed in to the fire. Jehovah may leave these weeds inside the congregation for a long time until the "harvest" or Armageddon. Bad elders are likened to rocks hidden below the water, because they "sink" boats [ brothers & sisters] in the congregation where they are drownd by Satan's world. These bad elders may also stay in the congregation until the end of this system of things. Jehovah leaves them in the congregation so you have the opportunity to stand-firm against Satan's tests like Jesus did in the wilderness; Matthew 4:1-12.
If you have been stumbled by either a weed or a rock under the water, then you failed the tests against you. This is nothing to be ashamed of,because "We all stumble MANY times" James 3:2, none of us are perfect. Even the Apostle Paul,an anointed Christian, had to fight constantly against his imperfection
As a practising JW, according to their teachings, you have the parable of the wheat and the weeds all wrong. Firstly they teach that the wheat are only anointed JWs, therefore 99% of JWs are not even considered to be 'wheat'.
You say that Jehovah leaves the bad elders in the congregation until the end of this system of things. This is riveting stuff. It wasn't God that put these elders there in the first place so it is the responsibility of the Governing Body to remove these bad elders. God isn't leaving them there so christians can be tested, the GB are just making excuses because they are failing in their job to ensure there are only men who properly qualify. Instead of cleaning up their mess they tell the sheepies to not even murmur against the elders and accept their wrongdoing without complaint - you will find these commands from the GB in even recent magazines. They don't even suggest you move from one congregation to another, you are just working outside the loving provisions provided by your leaders. In fact, often times, they have suggested to these bad elders that they move from one congregation to another.
You also state that these bad elders are planted by Satan. This is not what you are taught, in the past the GB say they have been appointed by Holy Spirit.
How can we even take you seriously when you yourself are going well outside of the WTBTS's own teachings?