Don't be upset. It is Christmas!!
It could be network or it could be your account
First, login to My Account and check if your account status is active or suspended. If suspended, maybe Pre-Authorized payment failed? just manually pay and you will be all good
if active, then try to reboot your phone once
Still, failed, try to reseat your sim card. Power off phone, take sim card out for a minute before putting it back in and power up
Of course, you can also try you phone at different area, maybe just a local outage