How to help baby monkey with chained ?

I went to buy seeds to prepare for a new planting season and went to an acquaintance’s house to buy chicken eggs for my daughter. My family loves eating chicken eggs and I often buy them here. Because they are cheap and have a safe origin. When visiting a chicken farm, I accidentally discovered a baby monkey chained to a pole and crying. I am a person who loves animals very much and I really feel heartbroken. My mood all day today is not good and I can’t do anything. What should I do to help that baby monkey now? I tried to buy it back but the owner of the chicken farm did not sell. This baby monkey was brought home by the owner’s nephew and chained there. full detail in the video