No case number in pink colour form 221(g)

Last week I have attended the us interview for L1B visa, it is refused with 221(g) form stating not clearly approvable without any case number. How could I come to know the case number or the case status. Please help me.

Pink form is usually given for background checks. Did they keep your passport? If yes, you can track it on VFS site using the passport number. You can also call VFS and ask them for status by providing HDFC receipt number and passport number.