If you really want to pre-pay your bill, the simplest way is set up automatic bill payments through online banking, assuming you use online banking. If your bill date is the 7th of each month, you can set your payment up for the 1st and never have to worry about your bill assuming you don't have other charges added to it.
The other option, not being pre-paid but just as good, is with Koodo self serve. You can set up pre-authorized payments so that when your bill is due, Koodo pays the bill from either the credit card or bank account that you provided them.
Both solutions ensure your bill is paid on time. Hope this helps