call-forwarding is enabled, directing the incoming call to a different number -- login to My Shaw, and check;
volume on your Panasonic is set to "zero" or "mute" -- use your mobile-phone to call your Panasonic phone, and watch your Panasonic, to see if any of its lamps light-up, or if it vibrates;
change to a different hand-set, and try #3, above;
dead battery in your Panasonic base-station, or in your handset;
your handset needs to be re-synchronized with your base-station.