If you received a “Revocation Letter” file a referral to a provincial judge under S.74 of the Firearms Act. This will at least get you past the 30 days which was given as a deadline to act.
Here is a link to the Ontario form:
https://drive.google.com/file/d/1iUV_oRvz_Qo2p0LrDfbXEKuqnSU5q47m/view?pli=1
Here is a link to the Ontario form:
https://drive.google.com/file/d/1iUV_oRvz_Qo2p0LrDfbXEKuqnSU5q47m/view?pli=1