Payroll Activity Statement does not balance with Payroll Reporting

My Activity Statement does not balance with Payroll reporting.  I had to reverse a payroll payment, it shows in the balance on an activity statement but when checking the amounts reported to the ATO it hasn't come off the employees balance.  It is now just sitting in the prepare electronic payments area - I can't delete it, I can't reverse it from that area (very annoying).  What do I need to do to make it balance - the activity statement is correct.