why i am not able to see SGB (Sovereign Gold Bond) into my Demat account?

why i am not able to see SGB (Sovereign Gold Bond) into my Demat account?

SGB can be bought through primary public issue or through secondary market . While applying to SGBs through primary issues, you need  DP ID and correct bank details. Fill correct DP ID  in the application form else SGB will not be credited into your Demat account and there will be issues in interest credit process too from issuer's end. 

SGBs are not visible in the Demat account. Reasons are following.
1: Wrong DP ID provided during filing the application 
2: Issuer takes 10-15 days to transfer into Demat account post issue closing date.
3: Paper form of SGB is bought.