I was at work the other day when I get a phone call that went like this. I'm me she's Irrational Lady (IL).
Me: Thank you for calling *store* this is me how can I help you?
IL: (please picture a super snotty tone for her) Yes I was just in there and I bought 20 cans of cat food and it was supposed to be 20% off and I didn't get my 20% off!
Now because where I work likes to torture us employees personally when something is on sale on your receipt it will have the full price listed, then wayyyyyyy down at the bottom, it'll have a "coupon" that takes off the discount. A lot of people miss it, I've been yelled at many times.
Me: Could you check on your receipt down toward the bottom after subtotal, is there a black bar that says coupon, with money taken off?
IL: There's nothing.
Note she answered way too fast to have actually checked but whatever.
Me: Well that's strange, the brand you bought is definitely on sale. If you come back we can re-ring it and refund the difference.
IL: I'm on my way home, OBVIOUSLY I'm not turning around.
Me: I can't do anything without the payment method here, our system doesn't store credit card information.
IL: Well YOU need to fix that!! This is ridiculous, you have a sale up, and I didn't get the sale, you need to fix this now!
Me: I understand it's frustrating, but I can't fix this for you, unless you're here.
IL: Well I'm never shopping there again!!
Me: Okay. Have a nice day.
I still don't know what the hell she expected me to do. Issue a refund with my magical powers? If I had any type of control over things like that she wouldn't have been talking to me in the first place. The people with the power are at corporate. I did get curious though since that sale has been going for awhile (it's about to end in fact) and any kinks would have been sorted out weeks ago. I looked up her receipt...she only bought 18 cans. You have to buy 20 or more for the sale price. I really hope she got home, looked at her receipt and felt like a fucking idiot. I doubt it, but it would be nice.