Late Fees not calculating

Late Fees not calculating

I have an invoice sent to the client on July 31, 2012.  It was due August 31, 2012.  The late payment interest charge is 2% per month.

The balance is $7947 (without taxes) It's only showing $103, which doesn't make any sense.  It should be 2% compounded to 7 months to $9128.