King1990,
As I always say, the rule of thumb to any TR application is to have valid status.
1- IRCC didn't see that you had valid student status (valid SP).
2- A PGWP cannot be restored. It can only be extended in cases where the applicant was eligible for a certain duration on their PGWP but their passport was about to expire. In cases like these, applicants are advised to first renew their passport, then reapply to extend the PGWP upto the duration (date) they were eligible for.
To fully understand your situation, ask yourself these simple questions:
a) When did I receive a confirmation letter from my DLI stating that I have completed my program and will graduate? In other words check for the date on that document.
OR the date your Official transcript was printed.
b) When did my SP expire? Did I apply after it expired?
c) When did I apply for a PGWP?
d) Did I apply within 90 days of receiving a confirmation letter from my DLI?
e) When did IRCC confirm the receipt of my application?
If your answer to b) and d) is Yes and No respectively, then let your lawyer take charge.
Cheers and Good luck!