unauthorized upgrade with stream+

That is strange. You should be able to manage your subscription and make your plan change on your Self-Serve account. https://www.koodomobile.com/en/help/stream-plus

In the meantime, I would suggest you to fill out the form in the following link to submit a request for a refund of the difference between the two plans. https://www.telus.com/en/subscription/supportform

The bundle can change on its own if Netflix gets switched from the ad version to premium, for example if an existing Netflix Premium account was linked during activation. Basic only comes with Netflix standard with ads. Did you link a Netflix account you already had?

You can log in to Self Serve, go to Subscriptions and select Manage under Stream+ to check which tier is showing. If it still says Netflix Premium, switch it back to Basic so you don't get billed for it again next month. For the amount already charged, the refund request goes through the TELUS support form, pick TELUS Stream+ as the option https://www.telus.com/en/subscription/supportform

more info here https://www.koodomobile.com/en/help/stream-plus

​@Gail for Dan 

We have looked into it and as ​@Dinh suggested, this happens when the Netflix subscription that is linked to Stream+ is switched from Standard with ads to Premium. You can change it back to standard with ads from your Netflix account before the next payment for your Stream+ subscription.