You have not replied to my query as to what state this is in, so I will provide a general answer and if you reply and tell me what state this is in, I can better tailor the answer to your state.
A POA is not enough. If your father has Alzheimer's, then any POA he signs is automatically void. The same applies to your mother if he has cognitive problems, because anyone who signs a document that they do not understand is not bound by that signature. While it is true that (a) the POA will be thought to be valid unless challenged and (b) whether or not they understand what they are signing is up for debate, a POA nonetheless does not take away their ability to act on their behalf. They can still take out money from their accounts even if they give you a POA, for example. And, they can void the POA at any time, and may be talked by the scammers into doing so.
Unfortunately, the only way to get control over your parents' finances is to get a guardianship order over them. A guardianship order will allow you to control their decision-making abilities, make decisions for them, and override theirs. It would be as though they were minors and you were their guardian.
Yes, you would have to go to court for this. If you tell me what state, I can better explain how this is done. Good luck.
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