Did you pay with a preauthorized credit card payment or debit payment from your bank account? 

The email above mentioned that if you used your normal bank account (not credit card) to setup preauthorized payment, when there wasn’t enough fund, you might be charged  for NSF fee. It only applied to preauthorized payment setup.

As you mentioned in another topic, you had issue with the bank account due to a hacking event. In that case, you need to remove the preauthorized payment approach and pay manually by either credit or online banking.
Regarding the NFS fee, if you were charged by Koodo, try to contact them by schedule a call back and ask them to waive it. Hopefully they can do it for you.

@Dinh Ok Thank you for your assistance.