Check on the final page(s) of your current and last bill and see if there is any notice of your plan price increasing.

hi Allan, thank you for your response.

I checked, the expiry note (as pasted in my original question) appear in today and last months bill, not before. There is no statement explaining, no notice of an increase, no indication of what it will be better month.

so I scheduled a callback, rep explained that it was just the code for my plan tht is no longer compatible with their systems. Effective tomorrow I would have the same plan just a new code.
Then he suggested a new plan for me: $30 for 1 Gb and UL minutes. BEtter than my current plan.
Thank you koodo!