I can kind of see why DOCS wouldn't want to allocate resources in the circumstances. The child isn't with a stranger, he's with his grandmother, and while not ideal, sleeping on the floor at his grandmother's place doesn't necessarily indicate an immediate risk to the child's safety. Let's say the reason he's not with his mum is because his mum's partner is abusive, being with his grandmother is the lesser of those two evils (though of course, being with his dad is presumably the best option of all in such circumstances, but that would put someone in contravention orders of what I presume are some extant interim orders, no?).
So, when you look at it like that, letting the FamCA/FCCA sort it out probably is the most viable avenue for DOCS at this stage, and it's not bad for you, either, because using DOCS to manipulate an outcome different to what the FamCA/FCCA has currently ordered isn't always the best idea for your case.
Put it into an affidavit - what the child has said and when, what the psychologist has said, any other evidence that cements your concerns, like if grandma is the only person who attends changeovers, for example. The court will probably have some questions if the issue is brought to its attention.
So, when you look at it like that, letting the FamCA/FCCA sort it out probably is the most viable avenue for DOCS at this stage, and it's not bad for you, either, because using DOCS to manipulate an outcome different to what the FamCA/FCCA has currently ordered isn't always the best idea for your case.
Put it into an affidavit - what the child has said and when, what the psychologist has said, any other evidence that cements your concerns, like if grandma is the only person who attends changeovers, for example. The court will probably have some questions if the issue is brought to its attention.