Owners cheat on slaves

Jeremiah 34:1-22
So all the officials and people who entered into this covenant agreed that they would free their male and female slaves and no longer hold them in bondage. They agreed, and set them free. But afterward they changed their minds and took back the slaves they had freed and enslaved them again.
Therefore this is what the Lord says: You have not obeyed me; you have not proclaimed freedom to your own people. So I now proclaim ‘freedom’ for you,declares the Lord—‘freedom’ to fall by the sword, plague and famine. I will make you abhorrent to all the kingdoms of the earth.
The date is still 588/7. After receiving God's message, King Zedekiah issues an order to free all Jewish slaves, perhaps hoping this will win God's favor.
The law said Jewish slaves  should be freed after six years, but the practice had lapsed. Now the owners free their slaves but go back on their under-taking to make this permanent. The slaves are forced into slavery again - and Go condemns the owners as law-breakers.
Why?
Since the law is announced to free their Jewish slave after 6 years but they did not practice it. Now before the enemy Babylonians, king make this order and the owners of slaves made covenant before the Lord, but afterward they changed their mind and forced slaves back. So it made God's angry and they will be freedom to fall by  the sword, plague and famine.
People see the nearby profit and gain the benefit, but they forget the promise and justice.
How?
Do not gain the benefit and forget the justice, God knows what we done. Take care the poors and needy people.