E.I from mat leave to sick benefits help!!

Hey everyone I wanted to ask a similar question that was asked but my situation is a little different. Ok so my youngest son is 10 months and I'm on maternity leave I'm supposed to have surgery next month (dec) and I have to go to work dec 20th I'm on e.i and that's when it ends now someone was telling me I could call service Canada and ask to add extra weeks for a sick benifit well I'm still on e.i so I'm do confused because it says you need 600 hours to apply but I'm on maternity leave so i don't know how to go about it or what to ask them lol I'm going to call them tomorrow but thought I would ask if anyone knows what to do thanks everyone !   

Tell them that you're on mat leave, but have an upcoming surgery booked, which will take place around the time you're expected back to work - and how do they handle something like that?  Best to start now because you just know they'll run you around for awhile before you get something in writing.  And make sure you get it in writing, for proof.

I was back to work after two weeks.  I don't do any heavy lifting and I felt ready to go back.