With Pickware ERP you have the option to cancel and refund (partial) orders. As long as the items in question haven't been shipped yet, they can be cancelled immediately.
Depending on whether one or several orders should be cancelled completely, or individual orders only partially, the procedure for cancelling differs. Here you'll find more information on partial cancellation and full cancellation of an order, as well as on cancelling several orders at the same time.
Here you'll also find the process again as a video tutorial: