Adding a delete button when the call log window is opened (i.e next to the print or export button) would be useful.
In the programming world that is a very simple thing to implement.
I would even put a check box for "Do Not Track Call History".
Hopefully these changes can be executed in the near future on sprint.com for managing your account.
If you are only getting one day what is your bill close date if it was yesterday that is all you will have you many have to wait a day or two for the bill to print to see last months call