What can you do in a situation like this?

My foster mom has a 4 year old grandson, he lives some days with her and some days with his other grandperents, he can’t live with his perents because they constantly fight and they are involved in drugs and stuff like that. The last time Rylan ( the 4 year old) live with his perents was about 2 years ago, and what happened was that my foster mom had to go get him because at the perents house there was a party and there was drinking and drug use going on, and it was almost 10 and Rylans mom was giving him a bath while she was drunk, so the police was called and smy foster mom went and got him and she does not want to allow Rylans perents to have him back. And recently Rylans dad came over to the house with the cops because “ he wanted him back” while he knows clearly that Rylan is not safe around him, he keeps messing up, wont take theraphy or nothing so h can have Rylan back but yet he wants him back. The mom can’t have him eaither because all she likes to do is party and leave Rylan who knows where, and both of them are willing to do NOTHING to get him back. My foster mom made treatment plans so they could follow in order to get them back, she did this based on what social services does for perents to get their kids back, and still nothing was followed, she was ignored, and just more problems came along. Rylan started school but know he is changing schools because his other grandma does not want him going where my foster mom has him go to, only because she does not want to drive and spend the time to acchually do something for Rylan, and Rylan has a big trouble getting used to new things, he had a lot of trouble going to his new school and it was a huge pain, and when he starts to like school they change him. So, My foster perents want to get costody of Rylan but I think she called CPS and they told here there was nothing they could do. I don’t get why but that is what she got told. I’ve only been 6 months at this house, but I have grown very close to Rylan, and you can see that what he’s going trough is not a happy moment for him either. All I want to do is to help my foster mom and see what can be done so she has costody of rylan and so he wont have to go trough this anymore, the house changes over and over the perents fighting and all that crap that a 4 year old should not be going trough. Can anathing be done? Trough social services or something that can be done trough law or something? Thanks for the help you can give.