Sounds like you had a new guy checking you out who didn’t know about the discounts or didn’t care. The experienced pharmacist stepped in and applied the correct discount codes.

It’s just like with your taxes, you’re more than welcome to overpay on your taxes if you don’t know the discounts available to you.

In a just world the system would just apply all the applicable discounts without your input, but I guess that’s the free market in action. One pharmacy will lose your business for not applying the available discounts while another will gain your business for doing so. It’s truly fucked up.