Grandparent Need Advice on Possible Custody of Grandchild

We have a 6 month old grandchild, but the mother is never around. We are now pretty much full time provider for the child. The mother doesn't have a job nor does she bother to look for one. She can't afford anything for her son but has money to go out with her boyfriend (not the father) and buy drugs. She is never home and when she does spend time with her son she acts like she's been with him everyday by posting images on social media. She can not handle him nor does she have the patience to deal with her son as if she gives up easily. She has a habit of using things as a "tool" and she has used her son as a tool to get things her way. We have photos, videos of her using drugs, and even we have a chat transcript that says she has left the house with her son in a carrier and the father on FaceTime video chat so he can babysit him. She did that just so she can go something to eat. Thing is that biological father is now living in Arkansas and we are in Kansas. We have no proof of that other than a chat transcript between them. We worry so much for our grandson and our house is filled with everything a child needs while she has nothing. She choose to be with her boyfriend and party, and do nothing. I am sorry for the long post, I'm a very detailed person and wish for the safety of our grandson.

Please help

Grandparent Need Advice on Possible Custody of Grandchild