actually, it does not sound like in North Carolina the physician must provide a referral

"Termination of the Physician-Patient Relationship
The Board recognizes the physician’s right to choose patients and to terminate the professional relationship with
them when he or she believes it is best to do so. That being understood, the Board maintains that termination of
the physician-patient relationship must be done in compliance with the physician’s obligation to support
continuity of care for the patient.
The decision to terminate the relationship must be made by the physician personally. Further, termination must
be accompanied by appropriate written notice given by the physician to the patient or the patient’s representative
sufficiently far in advance (at least 30 days) to allow other medical care to be secured. A copy of such notification
is to be included in the medical record."