Customer service or waste of money?

I work the front store, including the photo department and I majorly fucked up today.

So, this lady had gone to the kiosk to do photos in store. They were just party invites, but they had a bunch of text and stuff on them so they took a while to do. After she was done and got the little print out receipt, she asked me about a promo deal on them.

I assumed she was talking about the coupon codes that only work when you order photos online, which was my mistake. I quickly ran over to the printer as it already started printing, and instead of pausing the order, I panicked and deleted it permanently.

She then elaborated and told me she was talking about the one already on the kiosk, which means she would've gotten the deal in-store. I panicked again because I had just completely deleted all her work and couldn't bring it back. So I stood there as she re did her whole order, it took a good 20 min for her to polish up everything.

So, when she placed her second order, of course, the photo system just decides to stop working. She waited a whole half hour while I panicked, juggling between customers (it was very busy), and the photo department.

She ended up leaving and I told her I would call her when the prints were complete. She seemed reasonably mad because I had literally just deleted her order and she had to redo it and then she had to wait half an hour only to not even receive her photos.

I ended up calling the help desk and it took another 2 hours before the problem was solved. I called her and I had told her I was gonna give her an extra 10% off of her photo order, so instead of 30% off with the promo, it was 40%. I genuinely felt horrible, I could tell this lady was already having a hectic day and I definitely made it worse, and it was my fault for deleting her order and then confusing the machine into not wanting to print her new one.

I cant price modify photo orders, so before she came in, I worked out the math on my phone calculator and then charged her a taxable item for what the order would've cost at 40% off. I didnt tell my manager and it was an extremely busy day shift so I dont think anyone cared (we were doing truck).

But, now that I look back on it, I feel like it was unnecessary and I definitely wasted money. I know CVS is very strict about all that stuff, and I know I didn't get yelled at by my manager, but I feel kind of guilty.

What do yall think? Customer service or wasting money?