@Mark79 if both phones have problem, very likely it is a local network issue
data and text work?
I would try in different area to confirm if it is network outage. But at the same time, open ticket with support as well
if it does not, next to test is to change the Preferred network or network mode to 3G only (WCDMA) and see if the phone connects. if not, then it is a local 3G network issue
@Mark79 maybe the renewal wasn't completed?
Please login to My Account and confirm the account status first. Or call *611 and check status that way
If account is suspended, make a manual payment to resume the service on My Account or on *611 (4 digits PIN required)
If account is already active, try to reboot the phone or reseat the sim card, or test the sim in another phone. Also, test the sim in another area in case it is just a local network outage