The subscription was created with API. Cancellation order was placed for this subscription, but its provisioning is never completed, it is stuck in Provisioning.
The subscription was created with incorrect dates (e.g. the last billing date in future).
Deletion Completed event (method OnServiceDelete) fails with an exception
Concurrent Billing Order has been processed, please cancel current order.
The fact that order does not fails is a bug with id #PBA-64570 ("Cancellation order may stuck in Provisioning"). Possibility to set wrong dates with API is a bug with id #PBA-64569 ("APIs to create subscriptions do not validate StartDate, LastBillDate parameters").
Correct the subscriptions
Last Billing Date, which is only possible through the database. Feel free to contact Odin Technical Support for assistance.