Do you get network reception where you are currently using the phone? If not, then make sure you enable the $0 international roaming add-on in self-serve.
If you get network reception, best to call Koodo tech support. Here are some troubleshooting options you can try rather than calling:
1. reboot your phone
2. try your Koodo sim in another phone (either unlocked or locked to Telus/Koodo)
3. try in inbound call (have someone call you)
Hope that helps.