How do I report a care agency for the dreadful care the provided for my mother in law, and breach of her trust.

Report them to the state licensing board and the Attorney General's Office of that state. Hopefully you are using a different agency.

Can you please advise me on where to report them

And you are still using this agency because ... ?

My mother in law is not confused really with it, besides they have admitted turning up at 7am. Also on the days they did not arrive until 11am instead of 8 , I was at her house and got her washed, dressed etc., I took the phone call from the agency after 11, trying to tell me someone would be there soon! I told them not to bother, then they tried to bill for the visit. There bill shows that every visit was by a different carer. After we took up the issue of someone letting themselves in unauthorised at 7am they said this would not happen again, it happened within a couple of weeks.

If this is the kind of service they provide, this agency should be reported to the licensing entity. But first be very certain of the facts. As Pam says, elders, infirm people, and people with dementia don't always get their facts straight. Do you sign for payment of hours? How many different caregivers are listed? Do they report their hours as starting at 8 am or 11? How do you know when they really start? Does the evening one sign in at 4 or at 6? How do you know the carer was unannounced? Could she have been calling all the way to the bedroom, "Clara, it's me, I'm here to get you breakfast?" and MIL wasn't awake enough to hear her?

You may need to work with a different agency. Or you may just need a better way to track what is going on. For example, can you call each day at 8:30, and if a carer is not there by then, call the agency immediately? Could you arrange for the carers to call you first thing when they arrive? (Many service people do this.)

I can well understand your frustration. Just be sure you really know what is happening before you act.

There are two possibilities. First the agency is doing a lousy job OR second, the patient is confused and giving erroneous reports. To be fair, I consider my MIL, 86, who told us the nurse was just there, when actually she was not just there. Or MIL said she never fell, when in fact she fell and ended up in ICU. Or that she needs to see the doctor in two days and does not remember she saw him two days ago. So unless you have witnesses to these accounts, I would take them with a grain of salt, or MIL might make you look stupid.