VOIP E911 is an FCC mandate. Write a detailed (but clear) letter to the FCC about the problem; carbon it to the corporate counsel at Carolina Net and to the E911 supervisor you spoke with, and to your state Public Utilities Commission. Send it certified mail, return receipt requested.
If you don't receive a timely response, you may have more luck contacting your state PUC than the FCC if you call them on the phone, but I'd call both, if I were you.
Thor Lancelot Simon snipped-for-privacy@rek.tjls.com
"We cannot usually in social life pursue a single value or a single moral aim, untroubled by the need to compromise with others." - H.L.A. Hart