Hi there,

this can be for several reasons. To check and see why there was a price change, you can download your PDF bill from your koodo self serve. This will outline all of the details of your most recent bill. If you don’t see any obvious changes, you can also download bills from months prior and see if there were any changes. Steps to do this can be found in the link 

https://www.koodomobile.com/en/help/viewing-and-downloading-your-bills

I checked latest bill and previous one.

Still don’t know why..

There is no carry over , late payment fee ,add on. It is just basic monthly fee is more than usual.

Is there any way I can talk to live oparetor ?

This is due to a rate plan price increase. On the previous bill where the price was normal, if you check the fine print near the last page there will be a notice of the plan price increase. It sucks, but if you're not in a 2 year contract they can increase the price at any time as long as they give you that "notice". You can either keep the same plan but going forward it will be the new price, that or you can check and see if there are cheaper plans in self serve. Unfortunately even if you talk to a rep, they will tell you the same thing.