They are being cheated, therefore, I highly recommend that all customers check the purchase amount! I've been to the store three times, and I've taken a beer for the promotion. There was no limit to my indignation when I decided to double-check the purchase amount! And it turned out that all this time I was considered the full cost, i.e., in fact, the sellers cheated and buying 3 paid liters and 1 free one for the promotion, they charged me for all 4 liters! To my indignation, they were talking some nonsense! I'm sure they practice this all the time!! Be vigilant, they also do not like to give checks, so that there is no obvious theft!!!