Always Check Your Receipts!

So, we went to _____ on Friday, and found some nice boxes and a tube of wrapping paper (vintage beer and ale label print). Two of the boxes were of similar design, but one was slightly larger than the other. The smaller one was marked down from $8 to $3, and the larger from $9 to $3. When I get up to the counter, everything rings up at the marked price except the larger box which comes up at $4, so the cashier calls the manager up. The manager goes over it a couple of times, then loudly comments on the fact that it is larger than the other box. Um, what does the one box have to do with the other? Are they not two separate objects? She then proceeds to inform me that the box should have been marked down to $4, and the $3 label was incorrect. I considered it, was it really worth saving just the $1? After a brief pause, I decided that the money had nothing to do with it. It was strictly a matter of principle. The label said $3, I think I should have gotten it for $3. I stated as much, and with many dark looks, they acquiesced. I'm afraid I tend to be a bit of a push-over in areas like this, so I was quite pleased with myself as I marched out of the store with my finds. I should have looked at the receipt.
That afternoon, I'm going over receipts and I pull out the one for this store. I purchased four items all total, and I notice that the receipt lists five. Much to my annoyance, I found that the cashier had not removed the item from the first time she rang it up. So in addition to paying the $3 for the box, I had also payed the $4 it originally range up at! I was so furious... as paranoid as it sounds, I know she did it on purpose.
So, next day we had to go back down to the store. Fortunately, I did manage to get my money back with little dispute.

Moral of the story, don't forget to check your receipts. : /