Why can't I remove the 'mark unpaid' button at the point of sale?

[Sarah09]

 This is troublesome. At our point of sale, we turn the monitor to show the customer the total. If a customer hits the “mark unpaid” button at the top left, a receipt prints out like it was paid and the customer walks out with merchandise and a receipt. 

why is this option not removable?!

[THIS_Skateshop · Accepted solution]

I have a rule to not let the customer touch the screen until the transaction is actually completed. The price is said out loud, ask if they are using cash or card, run it all through, then they can enter their number or email for a receipt.

There is a Shopify Customer View app that works as a second screen and is supposed to bring up the total, tax, and list the items purchased, but I dont use it.

If you have an old phone, It could be mounted to the table as a display/signature pad.