You likely don't gave data turned off on your phone or data is just leaking a little. If the usage is extremely low, then you can probably send a private message to Koodo via Facebook Messenger or DM via Twitter or call 611 to have it reversed.
@Lorna, where do you see the pay-for-use-data message. Based on your account you are on an unlimited Canadian minute plan and have data block on. I don't see any data charges for the last 3 months. I do see long distance call to the US though.