This is an opportunity to “please God” reaping rewards in the “coming age”. So, evil never triumphs over Good in the end of all things.
Hence, be glad for such “opportunities” to “suffer for good” since we will “reap the rewards” in the afterlife if we remain faithful.
The person who “sowed unfair treatment” will most likely “reap unfair treatment” in Hell (in the afterlife) as a fair recompense accordingly unless if “he repents” too.
Principle of Judgment includes:
“Woe to the wicked–it will go badly for them, for what they have done will be done to them.” (Isaiah 3:11)
So, be careful of ‘how you treat others’.