What are rights of legal guardian vs. guardian at litiem?

If you are legal guardian of your grandchild because of a parents meth addiction and the guardian at litiem is still granting overnight visitation to the parents even though meth is still being used in the home, what can you do to protect your grandchild? I am trying to help someone in this situation who feels as though the “system” is not helping her protect the children. Can you request a different guardian at litiem for the child? Can Family Services help? Can you get an order for a mandatory drug test for the parent? Any professional legal help or any help from others that have been in this situation would be greatly appreciated. Yahoo group is M-A-M-A, Mothers Against Meth Addiction which is for grandparents raising their grandkids because the parents are addicted to meth.