Admittedly a sick puppy is a shame and My Heart goes out to you for this.
BUT, You should look into Small Claims court to sue them for Defective Product (Your Pup).
Did you receive any paperwork showing that the puppy had been vaccinated against Parvo? (Required under NC Law if they are a licensed breeder) Not the Advertisment but actual Vet's Documents showing Dosage and Lot number of the Vaccine administered.
You can recoup up to $7500 in Small Claims court without having to hire an attorney.
Posting your complaint on ROR should have been your OTHER option. Call your county Court Clerks Office and they will advise you on what paperwork needs to be filed and how to serve Mr. Smith. If Mr. Smith does not respond to the Summons you will win by default and the sheriff can seize his property to pay the Judgment.
I know this does not make up for the potential loss of a loving animal.
Report his "Puppy Mill" to the State of North Carolina Animal Welfare.
Here is the Law:
NC Animal Welfare Act. (1977, 2nd Sess., c. 1217, s. 1.)
19A-21. Purposes. The purposes of this Article are (i) to protect the owners of dogs and cats from the theft of such pets; (ii) to prevent the sale or use of stolen pets; (iii) to insure that animals, as items of commerce, are provided humane care and treatment by regulating the transportation, sale, purchase, housing, care, handling and treatment of such animals by persons or organizations engaged in transporting, buying, or selling them for such use; (iv) to insure that animals confined in pet shops, kennels, animal shelters and auction markets are provided humane care and treatment; (v) to prohibit the sale, trade or adoption of those animals which show physical signs of infection, communicable disease, or congenital abnormalities, unless veterinary care is assured subsequent to sale, trade or adoption. (1977, 2nd Sess., c. 1217, s. 2.)
God Bless