I'm the Dad and Guardian of a profoundly vulnerable daughter. The care center Program Manager and caregiver had deliberately lied to me..

I would bring in an independent lab and have a blood draw and medication testing done to have 3rd party verification of what drugs are and are not being given.

It is not uncommon for aides to take drugs from their patients, that is why they have to have special licenses to dispense medications.

I would try to find a different place for your daughter, when you start being lied to or even believe that you are being lied to it is time for change.

As if this type of situation is not sad enough, you have to worry about her receiving the proper medications. I am sorry for your situation.

Providing incorrect information particularly about medications is not legal. Anyone giving medications needs to document it and if it is being documented and not being done that is falsifying medical records.
You could take this to court. If there is a lawyer that helped you with the Guardianship you could start there.
You could also go to the State Ombudsman and file a complaint.
You could also file a complaint with the State Health Department as they inspect facilities.
I would also talk to the police. If they say they are giving pain medications but not giving them where are the medications going? Are they being sold, being taken by staff? Neither legal and both theft as well as the possibility of staff being under the influence while working in a care setting. Not safe for anyone!!

While I don’t know the legal detail of that it sure seems to me that as her guardian you are in fact her as information and decisions flow so yes they would have a legal responsibility to disclose and ask your approval for any changes in medication. That said I don’t really have enough details but it sounds like a lie like this is probably hard to prove. It sounds like your daughter is in a full time care facility and they should have to record/prove everything dispensed but if someone records giving a medication dose without actually doing that and no one else is there... I don’t think I would expend your energy on that “I don’t believe you” battle, personally I would expend that energy in rectifying the situation. To start if a doctor has prescribed pain medication for your daughter seems like that doctor should be a learned that their patients t is still in a great deal of pain, almost as though she weren’t getting that medication... I would also be looking for a new facility or caregiving situation, once trust breaks down this way it’s very hard to reestablish. It may very well be that from the Program Director and caregiver perspective their hands are tied somehow but it doesn’t really matter if they aren’t taking the care to make sure you trust what they are doing, rectifying the situation somehow to put you at ease which is a shame but all you can really do is move on from here. That may mean making sure you or someone you trust is around to witness medication administration until you can change the caregiving and make strides to do that quickly or it may just mean closer oversight until you feel like they got the message and it wont happen anymore, its hard to suggest a better remedy without more info. But you certainly don’t have to accept this, nor should you. I hope there is just a simple explanation you aren’t getting, good luck!