unanswered calls not going to voice mail

Hi

Voicemail and Call Display+ are included in all Canada-wide plans, so the plan change on its own shouldn't have removed it. Which phone are you using? If it's an iPhone, check whether Apple Live Voicemail is turned on, some customers do have problems with their Koodo voicemail when it is. I would also reset the network settings and restart the phone, then have someone call you and let it ring out to see if it picks up.

Koodo's voicemail page is here https://www.koodomobile.com/en/help/voicemail

I have done all of the above, still doesn’t forward the unanswered calls to voicemail.

iPhone 15, have never used live voicemail and it is turned off.

That is strange. Just to confirm, what message did people hear when the call wasn’t answered? 

Can you turn off your phone and use another device to call your number to see whether it reaches your voicemail and triggers a voicemail notification once the phone is turned back on?

The phone keeps ringing, never goes to voicemail. Have turned off and on and repeatedly called, phone just rings.

What if you put your SIM in someone else’s phone? Does it go to voicemail or not? 

Did you restart your phone after changing your plan? Have you tried to reset the network settings on your phone or update the carrier settings? https://support.apple.com/en-ca/109324