Duplicate Events in outlook client, office 365 web mail on macbook

I work at a school where we are all running macbook pro's with office 2011 for mac installed on our machines. We have been setup with our own office 365 organizational account where alot of us decide to use the outlook client by office 2011. I have a users computer that is showing multiple events in her calendar, it duplicates events, some events show 10 to 15 times on her calendar. Events such as birthdays, meetings and various appointments. Other users have shared they're calendar with my problem computer, giving me access to they're appointments and events and such, so I don't know if that can help with a solution, but I am seeing these duplicates happen in office 365 calendar, outlook client, iCalendar, and the users iphone. The duplicate events and such show up for months and months, so before I start deleting one by one and then just refreshing the app to have them all come back again, has anyone found a solution.