That's a terrible situation. Since she can't keep to the terms you agreed, I definitely think you should not return, and also because she is not helping.

Did she have you sign paperwork at the beginning of your work together that specified things about billing--like that she would file insurance for you, or that phone sessions were not covered by insurance?

I would send her a registered letter requesting that she send you the paperwork to file with insurance within 7 days or you will take legal action. You can't get the money you are owed until she does that, and she needs something more than reminders and requests, apparently. I'm sorry you have to go through this.