I would definitely terminate with her. Send her a certified letter saying her services are ended and submission of all past documentation to your insurance company is expected by such and such a date AS WELL AS copies of all such documentation be given to you (so you can file it yourself if needed or use it if necessary in lawsuit). Also, if she is a provider under contract with your insurance company, contact them and let them know what is going on. If she is not upholding her end of their contract, they will want to know that and can have her dropped from their contract. We've had to do that with a medical provider who was not following the guidelines of the insurance company and it was costing us money that it should never have cost us.