Old unpaid service invoices?

I have some old unpaid service invoices from 4+ years ago. 

With the new way Sage works, I am no longer able to remove terminated employees, at the end of the year, who have time associated with invoices that are still in the system.

Supposedly these are invoices that we will actually be able to collect on one day. 

Has anybody else encountered this situation, to be able to delete the terminated employees from the system?  (I hate having to keep old employees in my active Sage database.)