It seems like its the button itself not reacting to the phone to power on?
How long habe you had the phone for ? If your still under 1 year warranty you can go down to the koodo store and have them send the phone out for repair. You do get a loaner phone for free while your phone is being repaired. If your out of warranty best bet is to just upgrade to a new phone. If you still have a negative balance owing for the phone you can pay the remainder off upfront at the store, or on your next months bill.
I would have to agree with Teabird, if it is under warranty take it to Koodo to have it repaired.
For now I would suggest that you turn on the setting to launch the camera under lock screen. Setting-> swipe to application settings->photos and camera-> check "Press and hold camera button to wake up phone.
This will allow the camera to be accessed when the devi9ce is locked. Then if you back out of the camera it will take you to your home screen to unlock(if you have a password) and limit the need to the a reset when accessing the device