An user opens Uber app. [Xinhua]

Uber China, an online ride-hailing service provider, has been challenged by a number of complaints over the phantom cars charging customers for rides that never took place.

A woman surnamed Zhang recalled how several days ago she booked an Uber car for a journey from east to west across Beijing. But the driver who received the order took 10 yuan from her account but never showed up.

"The driver received the assignment as soon as I booked it. I thought he/she would have been coming round to pick me up while the journey status on my app showed ‘already in car'," Zhang said.

"I tried to contact the driver [after I had been charged 10 yuan], he/she didn't pick up the call."

The ubiquitous "phantom cars" are annoying the ride-hailing service in big cities, such as, Shanghai, Shenzhen and Chengdu, in addition to Beijing.

Uber China promised to refund Zhang within one or two working days while discrediting and punishing the driver.

The loophole may result from drivers' one-sided manipulation using an accomplice who captures the ride-hailing booking by dozens of cell phone numbers.

However, investigation into such frauds entails the efforts of security bureaus. Meanwhile, perpetrators arrested in Beijing and Shanghai can face a penalty as severe as one-year imprisonment.

Passengers who are cheated by the phantom cars can contact Uber China's after-sales service to get refunds.

Didi announced at the beginning of August its decision to acquire Uber China operations, but the merger may hit a roadblock as the Ministry of Commerce, the country's antitrust watchdog, says it is investigating the case.