@annalena okay so your plan should definitely be fine (the reason I asked is it's quite possible to run out of minutes on the $10 plan, but that is the only plan to which this issue applies so you're good there).
Can you confirm that you didn't change your phone's preferred network type to 4G/LTE-only? If you did, you would still be able to use data and texting but not be able to make phone calls.
Other than that, at this point if you haven't already, I'd definitely recommend you send a private message to the moderator team for assistance, as there may be a glitch with your account in the back-end systems. To learn how to private message the moderator team, please see here: https://productioncommunity.publicmobile.ca/t5/Knowledge-Base/How-to-Get-Help/ta-p/251745