Up to Commerce 7.5, we did not support to "cancel" the payment from Commerce Manager and payment workflows. It is indeed being considered as a feature request, and we might implement this in upcoming release - based on customer's feedbacks.
Not sure if this can help you
Using Commerec Manager you can create a return and can develop a PamentGateway to ProcessRefunds.
Or You can add a tab with your order details window and can add process refunds from commerce Mannager.
Thank you @K, that's a valuable link you've posted!
What solutions have you guys realised in order to cancel orders, i.e. when you have to refund/cancel the payments? Or when you made "test" purchases incl. payment gateway on the Live system?
Any experiences regarding situations where you sell only ONLINE products (i.e. no physical items that will be shipped), like e-Books or similiar?
I would be very interested to see some example implementations how to achieve this kind of "Cancel Orders" in EPiServer Commerce!