Although GetOrders returns basic information about Order Cancellations and/or Returns in its response payload (e.g., OrderArray.Order.CancelReason, ReturnedOrderCountActual, etc.,) it is strongly recommended that the Post-Order API be used to manage cancellations and/or returns.
The Post-Order API is a RESTful set of operations that allow users to partially or fully automate post-purchase flows like returns, item inquiries, order cancellations, and buyer/seller disputes. It is available to buyers and sellers on the US, UK, Germany, Australia, and Canada (English and French) marketplaces. Although primarily used by sellers, there are some calls that buyers may find useful.
For complete information about using the Post-Order, refer to: