The company is a national retailer with local stores in my area. The website is incorrectly applying a coupon that I should have qualified for only by spending a particular amount on items from a certain vendor — but it was applying it to whatever I bought so long as I bought one qualifying item from that vendor (even though the amount of that item was well below the qualifying threshold). Basically I could buy one of the qualifying items and a bunch of other stuff, and the coupon covered 100% of my entire purchase. Zero cost to me for the entire online purchase.
When I went to the store to pick up my order (I discovered the error after i had checked out and I still wanted the items) I tried to pay for the items. They thanked me but told me the problem was with their online store and that their in store system was separate. So they gave me the items I had ordered and told me there would be no charge. And they said they would look into why the website was functioning this way.
I checked again today and the glitch is still there. I know I could order a bunch of stuff and pay nothing for it and could do it repeatedly. I'm not posting this because I want any kudos for doing the right thing. I'm actually posting because I'm realizing how much it's driving me crazy that someone else out there might be doing this right now, and how much I want the store to fix this so it can't happen!! I find my own psychological struggle with that to be a bit comical 🙂