Monitor your delete task to verify it completes. 

The possible states of a task are:

StateDescription
NOT_STARTEDScheduled but not started.
IN_PROGRESSCurrently running.
COMPLETEDone, either successfully or not.
CANCELLINGCancellation has begun but not yet complete.
CANCELLEDCancellation complete and any changes are rolled back.
GET

https://api.anaplan.com/2/0/workspaces/{workspaceID}/models/{modelID}/actions/{actionID}/tasks/{taskID}

ParametersDescription
AnaplanAuthToken:{token}Your Anaplan authentication token value.
workspaceIDThe workspace ID
modelIDThe model ID
actionIDThe ID for the delete action.
taskIDThe delete action task ID.

curl -X GET \ https://api.anaplan.com/2/0/workspaces/0a800b00e0000000f000001eab0d0000/models/F1111111C11111111B11111F1111E11F/actions/117000000002/tasks/C2A0B7082F2149E3AA52D167E1DD04D1 \ -H 'authorization: AnaplanAuthToken {token}}' \ -H "Content-Type:application/json"

{

   "task":{

      "type":"taskInformation",

      "taskId":"0690AA1C761F48549C3442A02F91D962",

      "currentStep":"Complete.",

      "progress":1,

      "result":{

         "failureDumpAvailable":false,

         "objectId":"117000000019",

         "successful":true

      },

      "taskState":"COMPLETE"

   }

}