for more information on the billing process, see here

Delete billing

yes, you can delete bills from the Tools->Maintain Bills screen.
Just select the bill run on the left.
And on the right select all the Meter Accounts for which you want to delete the bill.
You can hold down control and click all the ones you want. Or click the first one, hold down shift and click the last one to select all.
Then click the Delete button at the bottom.