The PivotConfigurator does not trigger any event when end user tries to add/remove columns/rows/measures. What you can do is to get the Kendo Sortable widget used in the PivotConfigurator and wire its change event:
Note that this will work only when one dimension is moved from columns to rows and vice versa.
If you would like to detect "remove" by click, then you will need to wire the click event of the tag itself.
In both cases, you will not be able to prevent deletion.
Please note that the desired functionality is not supported and the given information is just a guideline to help you solve your business requirements. Further support for custom implementation falls out of the scope of the standard support service.
Join us on our journey to create the world's most complete HTML 5 UI Framework - download Kendo UI