You can always try the ticket support. I was able to get problems issued from there. They can help you.https://www.publicmobile.ca/en/get-help/articles/submit-a-ticket
If you don't see it. It means they are only available for new customers. If you want to see what's your availabilities. You have to go to the app to check, on change subscriptions to see the plans available to you.
Nope. PC Mobile is doing it for everyone right now. Mine went up to 23$ to 25$ too. But it seems they are doing it to only the 20$ plans because around October, they did the same thing with plans of 15$ to 18$ too.