That is a nightmare.
I can only imagine how upset and angry you must feel,
I also would have gone straight to that stupid dentist and ate the head off him.That is outrageous.
You are doing the right thing having the filling replaced asap and you will know how to help your daughter so she is blessed to have a mother who is even aware of this issue.
Lots of children her age have a mouth full of that crap.( of little consolation I'm sure... that is perhaps not the point and there should be no amalgam placed at all)

When they gave out the vaccinations the other day in my sons class, I sent him in late so there was no chance they could give him the vaccine by mistake.Thanks to your story I will also make sure I am with him at a mercury free dentist.
the extra cost is worth it.
I hope it works out well for you and your daughter.