Working with native calendar

Hi, iam developing an app, which displays shifts for employees in native calendar. It works ok, but the problem is, everytime user reloads his shifts(get data from server and create events in calendar), i delete the old events first. User can choose, which calendar is used, and if he uses calendar, that is synced with google calendar, it doesnt sync properly, because it exceeds the limit of deleted events. Any ideas how to turn off this limit or workaround this?