Use 824 receipt number
1. When calling NVC, use the 824 receipt number.
2. I 824 is approved by the INS (Texas Service center). After approval, the file is sent to NVC and it takes about 45 days-1 month for NVC to get in touch with you after it recieves your file.
If NVC does not have your case number, then you would have to followup with TSC.
Thanks,
Kanaka