I am not familiar with "theft by conversion". If you believe that the tenant has stolen from you and you want to press charges you should contact the police. However, keep in mind that there may be statutes of limitation that would prevent you from pursuing this matter.
The information you obtain from this answer is not, nor is it intended to be, legal advice. You should consult an attorney for advice regarding your individual situation.
No, there are no debtors jails in NC. Unfortunately, that is the risk of lawsuits, many are never collected upon. Keep in mind that judgments in NC last for 10 years but can be renewed for another 10. You are coming close to your 10 year deadline. If the judgment is unpaid and not renewed before 10 years is up, you will forever lose the right to collect against your former tenant.
Have you attempted to execute on the judgment yet? If not, you may want to hire an attorney to see if there are assets you can go after.