If you are unable to receive a call on your device, be sure to check these two things:
Do not disturb mode: if this option is enabled on your device, alerts, sounds and notifications will be paused. Make sure it is deactivated.

• On iOS devices, this option appears with this logo
• On Android devices, you'll see the words Do not disturb.

Call forwarding: if call forwarding is active on your device, calls will be forwarded to another number. To deactivate all call forwarding, enter ##002# and press the call key.