Hello Robotic. I am not sure what deadline you mean. Did you get a deadline given by CIC?
If not, there isn't a deadline, they will just wait until they receive them.
I did send in copies of the receipt for the new medical exam, just in case they got misplaced.
Sending in the receipts won't speed up the process, won't slow it down either
I did it so CIC would be sure to know I had completed the exam and because it made me feel better to have something to do.