Duplicate billing & invoicing scenario

Hello,

I am facing an issue in my project.

There are installations for which duplicate invoices got generated but not visible on ES32.

Example from 01.02.2015 - 25.02.2015 initially an invoice will be there which is reversed

later for time period 01.02.2015 - 28.02.2015 is created.

Now in FPL9 , both are posted but only one is valid and availablein ES32.

Can someone help me in fixing or understanding this?

Thanks,

Nishanth