Task: Question Answering
Input (English): Context: Scores of people queued up to use a cash machine after it started giving out double the money requested. The cash machine, outside a Sainsbury's store in Barham Road, Hull, attracted a big crowd of people hoping to take advantage of the fault, on Tuesday night. Police officers were eventually sent in to guard the machine and prevent anymore money from being withdrawn. The fault is thought to have affected cash machines at supermarkets across the city. It is not yet known whether the customers will have to repay the cash or how much money was taken out. A spokeswoman for Humberside Police said, "Officers were sent to the cash machine to prevent anyone else from withdrawing anymore money. We have also tried to make contact with the owners of the machine." The spokeswoman said those who benefited from the fault could be traced and could face theft charges, but investigations would only take place if the operator made a complaint. The cash machine is owned by a company called Payzone, a spokesman later confirmed. He said the fault was due to the machine being filled with notes of the wrong denomination . An investigation is underway into the incident and the machine had been taken out of service, he added. The Payzone spokesman said, "The transit company which is contracted to service this ATM has filled it up with the wrong denomination of notes, meaning it is paying out double what it should have. " He could not say how much money had been taken out of the machine, or whether it would have to be paid back. It was understood that a number of cash machines in Hull owned by other companies had also been affected by this problem, he added. 
 Question: Who caused the cash machine not to work properly?
Output (English): the transit company.