In 2006, it was very simple. Take care of your hands:

1) You came to the box office with the goods, the goods broken, the money at the cashier
You are in a hurry, the check didn’t wait, you left.
3) Instead of printing the cheque, the cashier takes the “cancellation” and puts the money in his pocket.

The purchase is not fixed, but the goods in the store have become slightly less. The scheme is very ancient, and there are probably other options for resolution, such as video recording the reason for cancellation, but it is easier to leave this function to a specific person - the hall administrator or guard.