What do we, as grandparents, do to get the kids back from CPS?

My family is being abused by CPS system here. My daughter had a baby at 14. She is now 16. My grandson turned 2 last Friday. His mom had got into a little trouble then I found out she was doing drugs, not daily but she was still using them. I would turn her in every time I knew was using. She never used around the baby. We had her court, the day before her counselor was here at our house, helping her to clean up her room. CPS showed up and says they got a complaint that my daughter was probably going to be removed from the home by the judge the next day. We anticipated, so we went before a Notary & signed a temporary guardianship form giving me guardianship of her son. They also said they were told that basically I am high all the time and I fall asleep while talking to people. The CPS lady was here for less than 45 minutes. Our MST Counselor (is a court mandated reporter, is in our home a few days a week, as well as my daughter's P.O/CMO, here too, a parenting teacher 1-2days a week, both are Court Mandated Reporters) asked if she wanted to talk with her she said no. The next day we get done in court where they did remand my daughter. I got a message from CPS lady saying that they were removing my grandson from our home later and my brother would be coming to pick him up. He will stay there. I am grateful he is with family but he doesn't know them, or the people they let babysit him. The CPS lady says that grandparents have no rights. She is going to accept the anonymous complaint which is where I truly become confused because it is completely unfounded. My daughter’s bedroom was dirty (that is what her and counselor were cleaning her room, they had been setting bags of laundry and stuff from her room in our living room so she said that the living room was messy). There is pretty much every day a mandated reporter in our home and has never found anything wrong with me or our home. I've never been high. I never have taken any kind of illegal drugs.