sometimes the bills don't come in all at once, this is b/c there are
different departments who's in charge of the various components of your
hospital stay and they are not always necessarily rolling up to the same
billing department.
at a minimum, you can call your insurance and the hospital to ask for an
explanation - they owe you that much.
and you can negotiate - but the stupidest thing you could do is to ignore
and hoping it will go away. Usually it won't. the bill will end up in some
collection agency who will ring you up and ask you to pay up. By then your
credit score is already affected, which, unless you plan to buy houses by
cash only in the future, should care about.
we bought some furniture a while back and we mis-read the fine prints. by
the time we realize our mistake, we already paid a couple of thousands in
interest. so we decided to fight. but instead of talking to the finance
department, we went into the store and ask for the store manager.
long story short, we got the refund.