On Pre-Paid plan, can't call.

Im on Pre-Paid with a 5G device. I had my service working properly. Can't tell when exactly, but now I can't make calls. When I trry to make a call, it will simply make a beep and end call. 

I do have full signal.

I do have data.

My plan should be active for at least another 9 months or so.

I was able to make calls before.

I've checked and I'm not on Airplane mode, nor forwarding/blocking calls.

Is there something else I can do to fix this?