Redbox Bad User Interface

We got a promotion code for a Redbox movie rental somewhere, and I went to use it.
Evidently, the machine was not on its home screen when I got there, but on the search screen instead.  Consequently, the “rent with a promotion code” button was not visible.  I followed the only path available, which was swiping my credit card.  I expected a “promotion code” box on the checkout screen, but there wasn’t one.  Instead I got the dvd out of the slot.  Alice in Wonderland, if you want to know. <After this> the home screen came up, showing the “rent with promo code” option, but it was too late.
Well this is bad, I thought.  My first instinct was to just put the disk back in, but I decided to call customer service first.  They said you have to be on the home screen and I would be charged, but on the bright side, my promo code was still good.
This sort of thing enrages me, and I didn’t want to waste any more time on them, but Cathy said to call back and ask for a supervisor.
The new agent, (Hi Jessica!), gave me the same story, but kindly went off to fetch a supervisor.  I never got to talk to him or her, but they say they are fixing it for me, and will refund the dollar when I return the disk, and have cancelled the code.
Good – Redbox seems to be doing the right thing here, but it cost me a lot of time calling them, and it is costing them two expensive customer service calls.
Bad – The UI design seems wrong.  It shouldn’t be modal, with the customer having to choose between pay or promo before starting!  In my case, I never even saw the choice because when I got to the machine it was already on a search screen down the “pay” path.  It is possible some previous person left it that way.  I don’t know if there is a timeout back to the home screen, but adding one is the wrong fix!  A better design is to have the promo code screen as part of the checkout flow, where the “what is your email” already is.  Doesn’t even add a screen that way.
I’ll let you know if the credit doesn’t appear.  Netflix is starting to look better already, although we don’t watch many movies.