Hello Kevin and welcome,
Thats honestly both disgusting and utterly shocking conduct by the agency,
You should telephone the adult safeguarding team in your area and advise them of the situation (go off of the letter you have written and let them know you have written) because this is the sort of thing they will want to get on top of immediately as the agency is operating on the behalf of the council as such this reflects bad on everyone involved.
Of course the agency is pressuring you because the only play (and not a good one either) they have is hoping you second guess yourself and withdraw the complaints, stick to your guns.
They are about to have to dismiss one, possibly even two employees (as is implied 2 persons attend your grandmother, both would had been assumed to had known the “friend” was an unauthorised person) and at least one of those will receive a safeguarding strike on their DBS which will stop them working (legally at least) in a care setting again for the foreseeable future.
It will also affect their relationship with the local council they have undertaken the contract of care for.
As bad as this is, what makes it even worse, is the attempt at deception to conceal the presence of the “friend”, whatever the reason they should not had been in there, however the detail is in the wording, the poor use of the term “shadowing” by an employee acting on behalf of the agency, implies the “friend” is also an agent of the same company the carers are working for, who is observing as part of their training as a new employee.
Not merely someone deciding if they fancy the job or not… and again, they still should not be doing what they were doing.
They simply have no recourse, it might well turn out that this “friend” is of an outstanding character (good apple) but it doesn’t mean a thing, because without the DBS check in place, for all intents and purposes they could be anyone, a person with past/current criminal history, substance abuse issues, etc… and they went and bought them into a frail ladies home.
Rabbit hole goes deeper if your grandmother asked the “friend” not to be present in the property during their visit but they stayed (trespass). And we won’t even get started on the data protection breach (their presence made them privy to very sensitive information which puts the client at risk, for example key safe entry points)
Might be time to get a Ring installed on the door (camera doorbell).
If grandmother is alert enough, she can insist they display their identification too… though this should not even need to be asked.
Just so you know, I noticed this is your first post (and what a post), while you seem to have everything in hand, if you do happen to have any questions in relation to yourself and role as a carer aside from the content of this thread, we are here for you.
As well as your grandmothers well being, my concern is also shared with wondering just how many people they have visited like this and gotten away with before you pulled them up on it.
Simply shocking… you are keeping alot cooler than I would!
Best Wishes
-HB