Make sure you are using latest version of windows phone 8.1 thats officially,
LUMIA DENIM - 8.10.14219.341. as per Microsoft WebsiteMicrosoft.
If you are not getting to know about incoming calls or messages,
try resetting your phone in Setting > about > resetSettings > about > reset,
and if you have tried resetting and still facing issue,
you can get notification in Notification Center about phone and messages,
or you can add icons in Quick Status like,