To delete the last statement batch, go to 

Communications->Statements->Statement dashboard

Select the region

• Click on ‘Delete last batch’, which takes you to the ‘Delete batch’ page
• From the ‘Delete batch’
  • Select ‘Yes’ or ‘No’ for ‘Proceed with deleting batch’
  • Click on the ‘Submit’ button

A ‘Statement’ batch job (ref Batch Jobs) is created to delete the statement batch. While the batch job is running, the statement batch is marked as ‘Processing’. As soon as the batch job completes, the statement batch is marked as ‘Closed’