What are our options? We understand the protection LLCs provide, but can
people, especially sole members, just rip-off other people and then hide
behind the LLC? Does the fact that her and her LLC are one and the same
mean anything? Are LLCs the kind of protection that lets crooks do their
damage without worries?

We signed a contract with an accountant that ended up not doing a heck of a
lot for the money we paid her. The contract really was with her LLC, but
she's the only member and does all the work. There is no distinction
between her and the company. She has no employees.
Some time ago, we mutually decided to terminate the agreement, with her
recognizing (verbally and in writing) that she owes us a refund for at least
part of the money we paid her. However, she is being extremely difficult to
work with and it's clear to us she is not acting in good faith.
What are our options? We understand the protection LLCs provide, but can
people, especially sole members, just rip-off other people and then hide
behind the LLC? Does the fact that her and her LLC are one and the same
mean anything? Are LLCs the kind of protection that lets crooks do their
damage without worries?
Since she has completely cut-off communication with us, we see ourselves
with no other option but to sue her and will be including both her and the
LLC as defendants. Any comments on this course of action?
Thank you very, very much in advanced.
Ripped-off in Orlando, FL

An LLC does not shield its members from personal liability for their
own torts, such as negligence. (It may shield co-members not
responsible for the tort, and it may shield the member from debts
incurred by the business so long as the member hasn't co-signed for
them.)
State law varies on the extent to which LLC members are responsible
for liabilities other than those arising from their own torts. Florida
has a modern LLC law that exempts LLC members and managers from
personal liability for just about anything short of dangerous
recklessness or dealing falsely with the LLC itself, or anything (such
as professional negligence) that would justify "piercing the corporate
veil".
Thus an accountant whose work was so far below professional standards
as to amount to negligence, and who cost you money because her work
was negligently performed, would be unprotected by her LLC.
But if you merely terminated your relationship because you didn't feel
you were getting your money's worth, that's just part of your contract
with her LLC, any refund you believe you are due would be a debt of
her LLC, and whatever right you had to recover would be against her
LLC.

Ignoring a demand to pay a debt isn't bad faith, negligence, or any
other tort; if you've already broken business relations with her, so
that she has nothing to gain by being accommodating, it's good
business and not even impolite. I'd read it as an unstated invitation
to sue or shut up.