Is your number still being verifier on Koodo’s end or Apple’s

iMessage technically has nothing to do with Koodo, since it is an application that runs over mobile/data or WiFi, connecting to Apple. Unless as part of the verification process it sends you an SMS text, which maybe was lost.

Anyhow, as a troubleshooting step you might want to try de-registering your number from iMessage, which should allow you to try adding it again from scratch:

https://selfsolve.apple.com/deregister-imessage/

Have you tried any of these methods? https://www.iphonelife.com/content/how-to-fix-imessage-waiting-activation-error-iphone-4-different-solutions