Change condition to visitor due to deferral

[Vanessa.h.]

I deferred my admission to January 2019 so I have to change my condition to visitor. However, I have an application for study permit extension in progress. Do I need to change my condition back to student before January if both application are approved?

Also, I am confused on changing condition to visitor. My purpose of visit Canada from September to December is waiting for January courses begin, and I plan to stay in Canada until 2022 as a student not a visitor.