First thing to try is a power cycle.
If still not working after that my suggestion would be to install a softphone on your PC or smartphone and configure it with the SIP parameters of one of the accounts. Turn off or disconnect your OBi from your LAN as some ITSPs don't permit more than one device to be registered at the same time.
If that receives calls OK, then the problem is with the OBi202. If it does not, you probably need to get your ITSP to investigate.