Who do i call if my 87 year old great grandma cant take care of herself and my family claims that theyre -cont?

they claim they're taking care of her and the people who say this are my aunt and uncle they have a job nursing her [through a company] but they dont do it her house is a mess shes crazy now and the place she lives in is unhealthy. my family cant and wont take care of her she gets a monthly check and my aunt and uncle use all of her money on who knows what [probably drugs idk] what should i as the only other guy in the family do im 17 working and have a car so im not some paranoid brat something really needs to be done about this but what and who should i call?