I filed a complaint regarding charges and a letter was sent to my husband regarding this and I never gave permission for any info regarding myself to be given to anyone

You may want to check again... most married couples DO give that permission.. and you only have to do it once. It remains on file after that.

And I can't think of any good reasons NOT to have your spouse have that permission and a lot of very good reasons FOR doing it.

Why are you so worried about what you husband might find out.

Also... was it addressed to HIM by name (which would be wrong without a permission being on file)... or just sent to your house where he could read it?

I think there are issues here that extend way beyond a possible HIPPA violation.