Man, I used to get so annoyed when someone would ring up one of my grocery items wrong. If I wanted to get money back - sometimes substantial amounts, like when someone mis-stickered some flank steaks as filet mignon - I had to run back to the store, wait in line, explain my situation, wait for them to confirm the error, and so on. What a nightmare.
Fortunately, someone is using technology to make this less of a pain in the ass. If there's an error on your Target receipt, don't get mad - and don't go back to the store. Just call the phone number at the top of the receipt and ask for customer service. Explain what happened - in my case, Laura's Lean Beef was supposed to be on sale, 2 for $8, but rang up full price. They'll ask for your receipt ID and the VCD#, highlighted on the photo. Then they'll ask for the item number that was incorrect. If you paid with credit or debit card, they can issue a credit back to the card without you ever leaving home.