Hi Mickey,
Thank you for the clarification.
There is currently no service in AdWords API that you can use to retrieve the data/logs in the change history tab directly. As a workaround, to retrieve the changed entities for a customer account or campaign based on the given date range, you can use the CustomerSyncService.get method. However, please note that it is not detailed as the Change History. It will only return the entity IDs and the latest status of it.
Let me know if you have further questions