I sent my study permit to be amended from outside of canada

[liquicity]

So my study permit did not state that I could work while being a student, and I accepted a job offer at my university for next fall, thing is i needed a sin, but my study permit did not state that I can work. So since i was outside of canada visiting my family for the summer I decided to send my study permit to be amended so I can apply for a sin the second i get in the country again. But now Im afraid they wont be able to send my study permit in time before i travel back. Would they let me back in if i dont have the study permit with me? Can they issue a new study permit at the border stating i can work. I still have a copy of my original study permit

 

[liquicity]

Can anyone help?