Why is my phone not receiving calls?

There could be several reasons why your phone is not receiving calls. Firstly, check if your phone has sufficient network coverage in your area. Weak or no signal can hinder incoming calls. Ensure your device is not on airplane mode or have any call blocking settings enabled. Another possibility is a potential software issue which can be resolved by restarting your phone. It's also worth checking if your call forwarding settings are turned on, diverting calls to another number. If none of these solutions work, there might be a hardware problem or a SIM card issue. Consider contacting your service provider, Optus, for further assistance to diagnose and fix the problem.