Are you a prepaid or postpaid customer?

If you are a postpaid customer, you could follow this to get the new SIM and reactivate your number in a different phone https://www.koodomobile.com/en/help/reporting-your-lost-or-stolen-phone

Regarding the contacts, most “smart phone” uses your email address to save it online. (icloud (iphone) or gmail (android)) so you could keep the contacts even the phone was lost. If you have backups online, you could retrieve other data also,

Thank you for your response! I am prepaid customer. What should I do in this case and how can I get a new SIM card with my old number? 

You would need a prepaid SIM and switch it in prepaid selfserve.

I would suggest you visit a Koodo kiosk and ask a rep there to assist.

Alternatively, you can buy a new SIM card for less than $10 from Amazon or Best Buy and activate that yourself in self serve. You will need to connect your new phone to Viber, WhatsApp etc but that is just a matter of activating your number with the service again.

Thank you for your advice! But I am just curious how can I receive a new SIM card with my old number?

Maybe you now how can I do that?

The SIM card will be blank. Once you activate it in self serve, it becomes active with your old number.

And the good news is that your old SIM will be deactivated at the same time, so people who find your lost phone can't use your old phone to make calls etc.

Thank you Sophia! 

So as I understood you properly, I can buy a new Koodo SIM card, then activate it in self serve and I would have a SIM card automatically connected to my old number? 

That's correct! Make sure you buy a prepaid SIM card and you should be good to go

Just to make sure: don't activate a NEW account, but login at your current self serve and activate it there. Here’s the link: https://prepaidselfserve.koodomobile.com/

Thank you so much Sophia!!!