I think you're confusing yourself with OSAP cheque pick-up and OSAP papers. When you agree to use OSAP to cover your tuition, you have to go to Financial Aid to pick up your OSAP papers. The OSAP papers requires you to sign at least 4 or 5 times. When you sign it, this means you agreed to the government that you will pay that money back. You then take the papers to Canada Post in Titles Bookstore and they will ask several IDs, once verified, they will sign it off and send it to the government for filing. If you don't pay back what you owe, the government pulls up your file and use the papers against you in court.
This different if you got grants. Sometimes you will get grants and you can pick up the cheque from Financial Aid. Grants are money you don't owe to the government.
I believe you will get the papers only in September if you used 60% of your OSAP loan and the remainder of it is paid in full. Then in January you can pick up the papers and a cheque that is worth 40% of your OSAP loan. You don't have to do this if you don't want to owe the government more money.
That's my understanding of it.