Page History
...
Performing cancellations on QIWI payment via web-service have additional feature: system usually replay with successful operation status but (in some cases) it can replay with status «In Process» (responsecode=AS300). It is related to the delay of the status return from the QIWI payment system. To receive the real status you should perform an additional request for the order operations statuses in a few minutes later the cancel request. When several cancels are performed on the order then several cancel operations (type 300: cancel) will be returned with the request result. They will have different parameter billnumber (in extended format: 5700027202722028.3 – for example).
Web Service Detailed Description