"Your current plan does not allow us to connect this call"

I am on a 3GB unlimited text and call Canada-wide plan. Three days ago, I lost all cell service. I've been with customer service since Wednesday and nobody has been able to help me. They told me to get a new SIM, which I did. I still have the same issue.

Different reps are telling me different things, like that my phone is not compatible (when it is VOLTE compatible) or that it's because my payment method was deleted (which it was updated, but not deleted). I keep suggesting that FIZZ change my plan to see if this triggers anything, but for some reason, this doesn't seem like a possibility.

I cannot make or receive calls or texts. When I leave the house, I have no data. Can someone please tell me how this is possible in 2023??