I will post my timeline so it can guide few people.
I received 1year PGWP because only one graduation letter was uploaded with the application (technical issue). I raised multiple webforms, submitted all the required documents and even called IRCC. One agent (ircc) advised me to send in webforms to get this resolved. But, some other day, another agent (ircc) told me that the officer has taken a decision based on the documents I submitted with my original application and there will not be any change, since appropriate amount of WP is issued depending on the documents submitted.
I reached out to the MP (Member of Parliament) for my area and asked them for any help. They contacted IRCC on my behalf but were also told that extension is only possible in one scenario i.e. Applicant's passport was expiring and that is the only way an PGWP can be extended.
As all options were exhausted, I reached out to a RCIC lawyer and reapplied with an explanation letter listing my reasons to reapply. In a month, I was approved for a 3 year PGWP.
