An informal appeal for hardship is something you do. They do not help you do it, and in almost all cases, they discourage borrowers from doing it even though it is their right to be heard. The Canada Student Loans Program is a business and it pays hundreds of millions of dollars to one third-party business to manage the program's accounts and borrowers. It is not in their best interest to help you despite the heavily reliance they have on saying they do.
The statute of limitations is a law that, when it applies to you, the debt can no longer be recovered by legal process and recovery.
If you meet the criteria for a reading of your proposal and demonstration then they have to do take it into consideration with fairness. The criteria is just that - hardship with extenuating circumstances that illustrates your inability to pay - and will continue to impede your ability. It is a very comprehensive and time consuming ordeal. The only way for me to determine if you meet certain or all criterion is to do a thorough assessment and analysis. That takes anywhere from 45 minutes to 2 hours, depending on the degree and scope.
My company serves as a resource for student loan borrowers in making these approaches, and mediation. I am up to my waist in these types of cases because of the number of people in hardship that the governments and banks want to press down on.