Feature Requests

We use suspended sales for new customer deposits which are paid days/weeks before they come in to complete the service. I was wondering if there was a way for the system to offer a pop-up that there is a suspended transaction that needs to be completed when the customer comes into pay the balance. We always enter the customers name into the till at time of purchase so I wondered if that or the phone number could trigger that there is still an amount owing?
The reason for this is the time from deposit to completion as well as there are multiple employees that may be running things through the till and often they will not know that they should check the suspended sales for previous payments.
We have overcharged a few customers lately and I thought this may be an easy fix??