This is an example of why I never use a credit card in a bar or restaurant when traveling overseas. Scams like this I remember were common in the villes outside US military bases back in the day:
A promise of a fun night out at a bar in Itaewon left an American tourist with a booze tab totaling 17 million won ($15,000).
Seoul police said on Thursday owners and employees at three bars in Itaewon, Yongsan-gu, have been indicted without detention for overcharging foreign tourists.
One of the indicted bar owners, surnamed Lee, allegedly charged an American tourist 17 million won for drinks he had during his one hour and 40 minutes stay at the bar.
The tourist found out about this overcharging only after returning to the US and receiving his credit card bill.
Two other indicted bar owners allegedly conspired to rip charge a German tourist about 7.9 million won.
The police are investigating whether the bar owners deliberately intoxicated the tourist, as traces of zolpidem and other narcotics were found in his hair. [Korea Herald]
You can read more at the link.