Better to call IRCC and check with them that they have your Oath form. Once they confirm it, you not getting it is plain laziness on the part of the oath officer. Whenever oath officer processes it, you will have it.I have already submitted the oath form from a different Email ID, I did receive acknowledgement email from IRCC but still not able to download the E-Certificate from the following site.
https://portal-portail.apps.cic.gc.ca/signin?lang=en