roaming notification even though i did not leave Canada

Eh, 

Are you living close to the US border? Your phone can latch onto an American tower without you going anywhere, and that triggers the roaming notification. That notification is a generic notice though, it doesn't mean you're actually being charged. Have you checked your usage in Self Serve? any actual Easy Roam charge would show up there.

If a charge does land on an issued bill, you can submit it through Ask us to review a charge in Self Serve, accidental roaming like this normally gets credited https://www.koodomobile.com/en/help/ask-us-to-review-a-charge-on-your-bill

Which phones are you using? Koodo not showing in the network list is odd, and the menus are different on iPhone vs Android. For now I would turn data roaming off in the phone settings on both lines. You wouldn't be able to select Koodo if your area didn't have Koodo signal

if you see other networks including roaming networks, then it sounds like you are in an an area with no Koodo coverage and the best coverage seems to be with a roaming network,

In these cases, your choices will be to continue to roam on a foreign network and pay for roaming, switch to a Canada-US plan, or find a provider with better coverage in your area