@blamtyt and this is why it's best just to set up on autopay. If you know you don't want to lose your number then just set up on autopay, but I guess you took the risk to not be on autopay, not make any payments or forgot. You should have put a reminder in your phone calendar at least. But now it's pretty much gone, however you might get lucky and your phone number might still be available if nobody else in your city/province has taken it yet.
As mentioned already, suggest you get a SIM, go online to activate and check to see if your number is available. You could message a MOD but you might not get a response for a few days, which then means there will be less of a chance that your number will be available.
