If a store accidentally overcharges, buyers apply for a refund and the management, if it values their custom, pays up promptly and apologises. Not so, the Mass Transport Railway Corporation. When the MTR collected $30,000 in excess fares at Lai King station due to a malfunction at the turnstiles, it did not announce the error and express regret. The mistake only came to light due to the vigilance of passengers. The travelling public is left to wonder whether the MTR would have owned up if it had not been forced. They will also ask if this was an isolated incident, or whether there are other deficient machines deducting excess amounts of money from Octopus cards and stored value tickets in other parts of the network. In the light of these concerns, the amount involved in the mistake becomes secondary. Public faith in the system is equally important. That has been dented yet again, because of what appears to be not just an accident caused through software problems, but something of a breach of trust. When the Octopus travel card was launched last year, commuters were encouraged to believe that the SAR was in the forefront of hi-tech travel with the new smart card, the product of a joint venture between the MTRC and Creative Star, which runs the scheme. The card, it was said, would prove so revolutionary that before long, it would be in use in most forms of public transport, and passengers could hop from MTR to bus to ferry, without needing to open their wallet to reveal the card. Teething troubles, though irritating, were excusable. But after eight months in operation, the system is far from foolproof. The card does not always register immediately in passing the turnstiles. Top-up machines are often out of order. Most alarming was the incident in April when a bus passenger was held for two hours in a police station because he used a card which he had bought months previously, and which, due to the time lapse, the system had cancelled. The Lai King bungle backs up the case for bus companies, which hang back from using the Octopus card on all services, claiming that they need to check its 'integrity'. This allows the bus companies to go on earning excess amounts from passengers who do not have the necessary small change due to the coin shortage. Well integrated and efficient though the transport system may be, commuters are paying over the odds in several ways, and their tolerance level is waning. It may be difficult to repay the excess charged to affected customers, but the MTR still has much to do in restoring the trust of the travelling public.