I'm assuming you don't have "Airplane Mode" or some other misconfiguration/setting on your phone which is preventing it from communicating with the network. And that it's configured to use "Public Mobile" Operator, has Public Mobile APN settings, etc.
And I'm assuming that you've tried calling/texting several different numbers, not just one number. And that the number(s) you've tried are local, working, valid - as in, they can call each other (and should be able to call you) without any issues.
But if you haven't, then this is the first thing to try, lol, it may be the phone on the other end which has problems.
The next step is to login to your Self-Serve account, confirm that your current plan is active and should be working. If there's a problem (with payment/plan/etc) then you can correct it.
If there's "no" problems with your phone or with your account then there's a problem with the network - you can try moving a few miles away so you're in an area serviced by a different cell tower (your local one might be down or buggy for whatever reason) - but chances are this won't fix anything and you'll have to contact the mods to get things working again.
