How to check my remaining balance

If you ported your number from Koodo to Telus, then that automatically closes your Koodo account.

You can still login to your koodo account for 90 days after your account closes.  You can view your pdf ebill in your koodo self serve and pay accordingly.

For your Telus account, if you closed it, then it will Telus will send your a final bill.  Just make sure you have your Telus self serve account created so you can login to view your bill

From abroad, you can contact Koodo through FB private messenger. Are you getting reminders to pay your invoice or what makes you think you may still owe Koodo some money?

So I was in a contract which I had to void cause my immigration status changed that's what making me think that I still owe them money 

Did you get a new phone on a tab with Telus?

If not then there is no contract cancellation fee, you just need to pay for the month the plan was active

No I didn't get a new phone but my current phone is not paid off. 

Then your koodo bill will have the remaining tab and tab bonus on the final bill

https://www.koodomobile.com/en/help/Tab-bonus