Slpiting Payments work period report problem

Some times my customer pays half payments of the ticket total and later they settle the balance of the ticket amount, but the problem is they might pay it in the following day. to close WP, i just make the balance of the ticket to pre-order. so what happens is total cash value do not match in the next WP report. I do not want to put the balance in to customer account as a credit. here are some screen shots.

This is the case as you are in essence not closing the ticket and preorder is carrying the ticket forward to the next day - not splitting it between the two days.